While this transform ability may not be the cheapest, its certainly worth doing, as, once again, this Saga is brutal
Ulamog, The Defiler [Serialized] #383 Magic Modern Horizons 3 Keep track of your collection value over time
The card saw a reprinting as a Judge Promo, but because of how scarce these cards are, Judge Promotional cards often fetch a premium over other copies of an MTG card
Void feels like a much less impactful mechanic
Stealing Hangarback Walker is particularly awesome (but be careful not to flip Jace, Vryns Prodigy if you steal him)
In most Commander games, if you have a consistent way to hit your opponents over and over for progressively more damage, why bother removing your own creature