Hey, I got on here just to give you some pointers with your Slivers.
1. For card advantage, not technically draw power: I like to use Descendants' path (I run 2. Reveal top card at upkeep, if a creature sharing a creature type, put it on the field for free, if not, go to bottom of the library), Into the Wilds ( I run 1, reveal top card at upkeep, if a land, put it on the field, if not a land, put it on the bottom of the library. Does not count as land for the turn), and call to the kindred ( I run one. At upkeep, look at top five cards. Of a creature that shares a type with enchanted creature os among them, put it on the field, rest goes on bottom of the library).
These are better than draw power; as they stack, gets you tons of stuff for free, and you still draw for the turn.
2. Since you run gemhide + manaweft, mana colors are no concern. Especially if you get some lands like sliver hive, transguild promenade, and jungle shrine.
3. Get rid of Megantic Sliver, too expensive for too little. It hurts your mana curve A LOT. A muscle sliver would actually be more effective with its +1/+1
4. Get rid of watcher sliver. The predatory slivers are enough of a buff. This slot is better used for alternative protection, like hibernation sliver, so you can protect them from kill spells.
5. Blur sliver is more efficient than reflex sliver
6. Might sliver is also slow.
7. Groundshaker is also slow and if you combine galerider + two-headed or shadow sliver, the opponent will have little means of stopping the assault
8. Speaking of galerider, it is better thsn winged
9. Syphon sliver is good, and it stacks woth essence sliver, which also stacks with itself.
10. Spitting sliver is way too slow, use striking sliver or talon sliver, though striking is better since it costs 1.
Here is my deck, if you want to test it with proxy or something. It runs like a dream and has tons of utility and wincons.
Creatures:
X4 manaweft sliver (tap for any color)
X4 predatory sliver (+1/+1)
X2 diffusion sliver (if targeted by opponent spell or ability, they have to pay 2 or ot is countered)
X1 Sentinel sliver (vigilance)
X1 bonescythe sliver (doublestrike)
X1 screeching sliver (tap, mill top card)
X1 necrotic sliver (3 and sac sliver, destroy target permanent)
X1 venom sliver (deathtouch)
X2 blur sliver (haste)
X2 striking sliver (first strike)
X2 galerider (flying)
X1 syphon sliver (lifelink)
X1 essence sliver (lifelink without the keyword and wordes weird, so it stacks with syphon and other essence sliver)
X1 telekinetic (tap to tap target permanent)
X1 homing sliver (slivers get slivercycle for 3. Slivercycle: pay 3 and discard, search livrary for sliver, reveal it, put it in your hand, shuffle library)
X1 clot sliver (2 to regen)
X1 leeching sliver (whenever a sliver attacks, defending player loses 1 life)
X1 two-headed sliver (cannot be blocked except by 2 or more creatures)
X1 constricting sliver (may exile opponents creature until it leaves the field)
X1 hibernation sliver (pay 2 life: return this creature to your hand.)
X1 sliver hivelord (indestructable)
X1 sliver legion (+1/+1 for each other sliver in play)
X1 sliver queen (2: put a 1/1 sliver on the field)
X1 sliver overlord (3: search library for sliver, reveal, pyt in your hand, and shuffle. Also 3: gain control of target sliver)
X1 amoeboid changeling (counts as all creatures at all times. Tap: target creature gains all creature types until end of turn. Or tap: target creature loses all creature types until end of turn.
Enchantments:
X1 call to the kindred (read above)
X1 into the wilds (read above)
X2 descendants' path (read above)
X1 mana echoes (when a creature comes into play, you may add 1 to your mana pool for each creature that shares a creature type with it)
Lands: (there are better options, it is what I have, and it works well)
X1 of each basic land
X4 sliver hive ( tap to add 1 to mana pool. Or tap to add 1 of any color, but only to cast sliver spells. Or pay 5 and tap to get a 1/1 sliver)
X2 savage lands (comes into play tapped. Tap for swamp, mountain, or forest)
X2 jungle shrine (comes into play tapped. Tap for mountain, forest, or plains)
X3 Seaside citadel (comes into play tapped. Tap for forest, plains, or island.)
X4 transguild promenade (comes into play tapped. Sacrifice it, unless you pay 1. Tap for any color.)
Sideboard: (you can look these up)
X1. Fireball (burn EVERYTHING)
X1 liquimetal coating (Turn EVERYTHING to an artifact, but only one thing until end of turn)
X2 splinter (remove EVERYTHING that shares a name with target artifact from the game. Bye bye basic lands turned to artifacts from liquimetal coating)
X1 root sliver (can't be countered)
1. For card advantage, not technically draw power: I like to use Descendants' path (I run 2. Reveal top card at upkeep, if a creature sharing a creature type, put it on the field for free, if not, go to bottom of the library), Into the Wilds ( I run 1, reveal top card at upkeep, if a land, put it on the field, if not a land, put it on the bottom of the library. Does not count as land for the turn), and call to the kindred ( I run one. At upkeep, look at top five cards. Of a creature that shares a type with enchanted creature os among them, put it on the field, rest goes on bottom of the library).
These are better than draw power; as they stack, gets you tons of stuff for free, and you still draw for the turn.
2. Since you run gemhide + manaweft, mana colors are no concern. Especially if you get some lands like sliver hive, transguild promenade, and jungle shrine.
3. Get rid of Megantic Sliver, too expensive for too little. It hurts your mana curve A LOT. A muscle sliver would actually be more effective with its +1/+1
4. Get rid of watcher sliver. The predatory slivers are enough of a buff. This slot is better used for alternative protection, like hibernation sliver, so you can protect them from kill spells.
5. Blur sliver is more efficient than reflex sliver
6. Might sliver is also slow.
7. Groundshaker is also slow and if you combine galerider + two-headed or shadow sliver, the opponent will have little means of stopping the assault
8. Speaking of galerider, it is better thsn winged
9. Syphon sliver is good, and it stacks woth essence sliver, which also stacks with itself.
10. Spitting sliver is way too slow, use striking sliver or talon sliver, though striking is better since it costs 1.
Here is my deck, if you want to test it with proxy or something. It runs like a dream and has tons of utility and wincons.
Creatures:
X4 manaweft sliver (tap for any color)
X4 predatory sliver (+1/+1)
X2 diffusion sliver (if targeted by opponent spell or ability, they have to pay 2 or ot is countered)
X1 Sentinel sliver (vigilance)
X1 bonescythe sliver (doublestrike)
X1 screeching sliver (tap, mill top card)
X1 necrotic sliver (3 and sac sliver, destroy target permanent)
X1 venom sliver (deathtouch)
X2 blur sliver (haste)
X2 striking sliver (first strike)
X2 galerider (flying)
X1 syphon sliver (lifelink)
X1 essence sliver (lifelink without the keyword and wordes weird, so it stacks with syphon and other essence sliver)
X1 telekinetic (tap to tap target permanent)
X1 homing sliver (slivers get slivercycle for 3. Slivercycle: pay 3 and discard, search livrary for sliver, reveal it, put it in your hand, shuffle library)
X1 clot sliver (2 to regen)
X1 leeching sliver (whenever a sliver attacks, defending player loses 1 life)
X1 two-headed sliver (cannot be blocked except by 2 or more creatures)
X1 constricting sliver (may exile opponents creature until it leaves the field)
X1 hibernation sliver (pay 2 life: return this creature to your hand.)
X1 sliver hivelord (indestructable)
X1 sliver legion (+1/+1 for each other sliver in play)
X1 sliver queen (2: put a 1/1 sliver on the field)
X1 sliver overlord (3: search library for sliver, reveal, pyt in your hand, and shuffle. Also 3: gain control of target sliver)
X1 amoeboid changeling (counts as all creatures at all times. Tap: target creature gains all creature types until end of turn. Or tap: target creature loses all creature types until end of turn.
Enchantments:
X1 call to the kindred (read above)
X1 into the wilds (read above)
X2 descendants' path (read above)
X1 mana echoes (when a creature comes into play, you may add 1 to your mana pool for each creature that shares a creature type with it)
Lands: (there are better options, it is what I have, and it works well)
X1 of each basic land
X4 sliver hive ( tap to add 1 to mana pool. Or tap to add 1 of any color, but only to cast sliver spells. Or pay 5 and tap to get a 1/1 sliver)
X2 savage lands (comes into play tapped. Tap for swamp, mountain, or forest)
X2 jungle shrine (comes into play tapped. Tap for mountain, forest, or plains)
X3 Seaside citadel (comes into play tapped. Tap for forest, plains, or island.)
X4 transguild promenade (comes into play tapped. Sacrifice it, unless you pay 1. Tap for any color.)
Sideboard: (you can look these up)
X1. Fireball (burn EVERYTHING)
X1 liquimetal coating (Turn EVERYTHING to an artifact, but only one thing until end of turn)
X2 splinter (remove EVERYTHING that shares a name with target artifact from the game. Bye bye basic lands turned to artifacts from liquimetal coating)
X1 root sliver (can't be countered)