In my (biased) opinion, esper control is good enough.
At worst, you're not really wasting money buying cards for this deck. Its basically a pile of staples, and if you later decide that UW or jeskai are better, you're most of the way there, and you aren't gonna be left with a lot of expensive cards that won't transfer.
Absorb is definitely appealing, though I can't say for certain if it will stick.
UW and Esper, not having access to helix, do care about lifegain. Most of us have played blessed alliance (which is nice but competes with push), timely (which is also nice but plays poorly with terminus), or rev (which is slow and clunky) at different points in time.
I would never sideboard this, but theres a real chance it sees play as a 1-2 of.
Sideboards vary.
I usually play thoughtseize + extractions or clique + rip, some copies of blessed alliance, some cheap countermagic, another sweeper or 2 (EE, settle, verdict, etc) sometimes halo, leyline damping sphere, or stony, sometimes night of souls betrayal, sometimes unmoored ego, sometimes disenchant/celestial purge/anguished unmaking, sometimes angels, sometimes other random fun cards.
Also, if people want to go back to the original wafo-tapa list with 4 mainboard meta-dependant cantrips, we're getting awfully close to the point that hallowed moonlight is playable.
It has a chance as a singleton. I've probably said this before, but it any 3 mana counterspell has a chance in modern, its this one.
I could see UW control splitting 1-1 mainboard with timely reinforcements, since you might want something thats better vs combo, but still functional vs aggro/burn.
Jeskai control in its current would not play twin nor stoneforge.
Jeskai twin was a deck in the past, and it was distinct from jeskai control. It likely would be in the future as well.
Same thing is likely for stoneblade. UWR blade is likely to be a deck if sfm gets unbanned, but its not the same deck as UWR control (its probably closer to the jeskai tempo decks we saw last year).
Having played a fair amount of myth realized, heres a few suggestions:
You want snapcaster mage. Its too good not to play.
You probably want to up the amount of burn you play. 4 bolt, 4 helix, 2 boros charm, (4 snap) maybe a forked bolt, electrolyze, etc. Especially instants, but even for sorceries. Being able to cast burn on their endstep while growing myth, then untapping is pretty strong. (also boros charm double strike can be pretty gross)
Chart a course is also a very tempting card for such a build. Its a little awkward casting it MP2 with myth, but not nearly as bad as prowess creatures.
You can loot away extra myths late game, or just keep cards flowing.
I also really don't like your mana base.
5 fetches is low, 6 shocks is high, and you have too many UR lands to support myth adequately. You can really never have enough white sources with that card.
its also a functional mana sink, making manlands less useful (which is nice because none of the jeskai manlands are very good in delver)
You probably don't want to spend removal on azusa or snakes. They don't have that many threats in their deck, so you can run them out.
Cavern is good, but they usually only play 1, and you do have removal. You can also counter summoners pacts.
You probably want both walkers vs scales, depending on the extent of your board.
Teferi is not great against burn, dredge, infect, and is pretty medium against storm.
I don't think jace is really ever worth cutting.
The matchups he's not good in, terminus is usually really good, and a turn 5 terminus + gain 3 life is better than a turn 6 terminus.
Most builds don't play hivemind anymore, and its almost unheard of to run 2 copies of pact of negation.
If your local meta was all control decks, they could do that, plus a second cavern, plus an academy ruins, plus a carnage tyrant or whatever in the board, plus whatever else, and you'll probably never win the matchup unless they mull to oblivion.
Assuming they're playing a reasonably standard build of the deck, they're not consistently going to have 3 pacts + hivemind.
Amulet is probably in our favor. At least, its probably not worse than even, barring strange builds.
You want to mull hands that can't beat an early titan, and you want to resolve a planeswalker.
Don't carelessly use your LD lands (cavern of souls, slayer's stronghold, and sometimes sunhome HAVE to die.) Blasting a rando bounce land on turn 3 is frequently not a great play.
You can very well run them out of threats, so you shouldn't feel too pressured to act.
Disallow is probably the best 3 cmc counterspell in the format, but its still a 3 cmc counterspell. The format is too fast for it to be worth a slot.
Censor is not good in this deck because we need our answers to actually do something in more than just narrow circumstances.
Playing it in the serum/opt slot is slightly better, though in my opinion, without terminus you should not play either of those, and in general, hiero is a better card in that slot anyways.
Dawn charm is just too narrow. A fog is probably not going to matter much, since we're probably still dead the next turn. Countering burn or discard is ok, but its still a 2 cost spell, and its going to do very little far too often.
I would rather play think twice than azcanta or 1 cmc cantrips, with the possible exception of hiero.
Dredge isn't consistently beatable without playing a ***** ton of hate + terminus.
As in, my build of 4 terminus, 2 surgical, 2 ego, 1 nosb, 1 angel isn't even close to enough. Adding 2 rest in peace to that is still not going to bring me up to 50/50, unless they're mainboard.
I'm on 2 seize 2 extraction 2 ego in the board right now.
Haven't played enough with it to really say, but so far I'm not inclined to change. Ego has been good for sure.
I've had some lines like bounce bridge + ego bridge against lantern, ego gemstone mine out of amulet so he can't pay pact of negation, ego valakut, etc.
If you're not on any miracle spells, think twice/hiero > 1cmc cantrips.
If you are on miracles (as I am) then you probably want the set of opts.
I'm not super high on settle the wreckage. If you feel its needed then you should probably just be playing terminus.
That being said, 1 copy of settle in the 75 is probably ok.
Most amulet plays don't cut amulets in the UW matchup.
They do in the mardu/jund matchups, but they need amulets to be able to pressure planeswalkers effectively.
That being said, I agree that if you see bloom/hive mind, you do want it.
At worst, you're not really wasting money buying cards for this deck. Its basically a pile of staples, and if you later decide that UW or jeskai are better, you're most of the way there, and you aren't gonna be left with a lot of expensive cards that won't transfer.
Absorb is definitely appealing, though I can't say for certain if it will stick.
UW and Esper, not having access to helix, do care about lifegain. Most of us have played blessed alliance (which is nice but competes with push), timely (which is also nice but plays poorly with terminus), or rev (which is slow and clunky) at different points in time.
I would never sideboard this, but theres a real chance it sees play as a 1-2 of.
For example lists:
with terminus:
2 teferi, hero of dominaria
3 jace, the mind sculptor
1 entreat the angels
1 sphinx's rev/search for azcanta
2 fatal push
4 path to exile
4 terminus
3 logic knot
3 cryptic command
4 opt
4 esper charm
3 celestial colonnade
1 creeping tar pit
2 field of ruin
1 swamp
2 plains
3 island
2 hallowed fountain
2 watery grave
4 flooded strand
4 polluted delta
1 glacial fortress
without terminus:
2 teferi, hero of dominaria
2 snapcaster mage
1 white sun's zenith
3 think twice
4 esper charm
1 sphinx's revelation
2 search for azcanta
4 path to exile
2 fatal push
2 supreme verdict
1 wrath of god
2 spell snare
3 logic knot
3 cryptic command
3 celestial collonade
1 creeping tarpit
2 field of ruin
1 swamp
2 plains
3 island
2 hallowed fountain
2 watery grave
4 flooded strand
4 polluted delta
1 mystic gate
Sideboards vary.
I usually play thoughtseize + extractions or clique + rip, some copies of blessed alliance, some cheap countermagic, another sweeper or 2 (EE, settle, verdict, etc) sometimes halo, leyline damping sphere, or stony, sometimes night of souls betrayal, sometimes unmoored ego, sometimes disenchant/celestial purge/anguished unmaking, sometimes angels, sometimes other random fun cards.
Also, if people want to go back to the original wafo-tapa list with 4 mainboard meta-dependant cantrips, we're getting awfully close to the point that hallowed moonlight is playable.
I could see UW control splitting 1-1 mainboard with timely reinforcements, since you might want something thats better vs combo, but still functional vs aggro/burn.
Jeskai twin was a deck in the past, and it was distinct from jeskai control. It likely would be in the future as well.
Same thing is likely for stoneblade. UWR blade is likely to be a deck if sfm gets unbanned, but its not the same deck as UWR control (its probably closer to the jeskai tempo decks we saw last year).
3 Isochron Scepter
4 Snapcaster Mage
4 Serum Visions
4 Mission Briefing
4 Lightning Helix
4 Lightning Bolt
4 Path to Exile
2 Boros Charm
2 Dawn Charm
4 Deprive
4 Remand
4 Spirebluff Canal
4 Scalding Tarn
4 Flooded Strand
2 Hallowed Fountain
1 Sacred Foundry
1 Steam Vents
2 Island
1 Plains
1 Mountain
1 Desolate Lighthouse
I'd be inclined to start with something like this if I wanted to play isochron.
You want snapcaster mage. Its too good not to play.
You probably want to up the amount of burn you play. 4 bolt, 4 helix, 2 boros charm, (4 snap) maybe a forked bolt, electrolyze, etc. Especially instants, but even for sorceries. Being able to cast burn on their endstep while growing myth, then untapping is pretty strong. (also boros charm double strike can be pretty gross)
Chart a course is also a very tempting card for such a build. Its a little awkward casting it MP2 with myth, but not nearly as bad as prowess creatures.
You can loot away extra myths late game, or just keep cards flowing.
I also really don't like your mana base.
5 fetches is low, 6 shocks is high, and you have too many UR lands to support myth adequately. You can really never have enough white sources with that card.
its also a functional mana sink, making manlands less useful (which is nice because none of the jeskai manlands are very good in delver)
Cavern is good, but they usually only play 1, and you do have removal. You can also counter summoners pacts.
Teferi is not great against burn, dredge, infect, and is pretty medium against storm.
I don't think jace is really ever worth cutting.
The matchups he's not good in, terminus is usually really good, and a turn 5 terminus + gain 3 life is better than a turn 6 terminus.
If your local meta was all control decks, they could do that, plus a second cavern, plus an academy ruins, plus a carnage tyrant or whatever in the board, plus whatever else, and you'll probably never win the matchup unless they mull to oblivion.
Assuming they're playing a reasonably standard build of the deck, they're not consistently going to have 3 pacts + hivemind.
You want to mull hands that can't beat an early titan, and you want to resolve a planeswalker.
Don't carelessly use your LD lands (cavern of souls, slayer's stronghold, and sometimes sunhome HAVE to die.) Blasting a rando bounce land on turn 3 is frequently not a great play.
You can very well run them out of threats, so you shouldn't feel too pressured to act.
Censor is not good in this deck because we need our answers to actually do something in more than just narrow circumstances.
Playing it in the serum/opt slot is slightly better, though in my opinion, without terminus you should not play either of those, and in general, hiero is a better card in that slot anyways.
Dawn charm is just too narrow. A fog is probably not going to matter much, since we're probably still dead the next turn. Countering burn or discard is ok, but its still a 2 cost spell, and its going to do very little far too often.
Dredge isn't consistently beatable without playing a ***** ton of hate + terminus.
As in, my build of 4 terminus, 2 surgical, 2 ego, 1 nosb, 1 angel isn't even close to enough. Adding 2 rest in peace to that is still not going to bring me up to 50/50, unless they're mainboard.
Haven't played enough with it to really say, but so far I'm not inclined to change. Ego has been good for sure.
I've had some lines like bounce bridge + ego bridge against lantern, ego gemstone mine out of amulet so he can't pay pact of negation, ego valakut, etc.
If you're not on any miracle spells, think twice/hiero > 1cmc cantrips.
If you are on miracles (as I am) then you probably want the set of opts.
I'm not super high on settle the wreckage. If you feel its needed then you should probably just be playing terminus.
That being said, 1 copy of settle in the 75 is probably ok.
They do in the mardu/jund matchups, but they need amulets to be able to pressure planeswalkers effectively.
That being said, I agree that if you see bloom/hive mind, you do want it.