MTG Salvation

Seems like he could work well with cards like sneak attack and "ach! hans, run!" in my cube, would like to know your thoughts on this improved polymorph on a walker. It seems very promising and with relatively few deckbuilding stipulations involved, I would run it in a deck where the creature top off at 3cmc with a few fatties in it and a few other methods of cheating them on.

Seems too niche. Looks underpowered by cube standards. I don't think it works that well with Sneak Attack/Through the Breach because you still need a few low cc creatures and so your chances of hitting something less than ideal are real. It will occasionally turn Inferno Titan into Ulamog, which is cool, but you were pretty likely to win with the Inferno Titan anyway. Also don't like the exile part because it prevents any shenanigans with Bloodghast, Seasoned Pyromancer, etc.

Lukka will be good in some decks, but I just don't think it will be good in enough decks to justify a 5cc spot.

Cheers,
rant

Looks like a cool card if you support the Polymorph deck, but otherwise it looks like a miss. That archetype is likely worth looking at now, as it's quickly approaching the critical mass it needs to function consistently.

Lukka hasn't performed that well in Polymorph combo, but he has performed very well in creature combo decks - I would do as far as refer to this as the Red Birthing Pod.