A 4/2 with menace can be hard to deal with, too, especially since Vona's ability can clear out blockers that would otherwise lead to Vona being destroyed by battle
You should absolutely play it
Summon: Yojimbo and Summon: Ixion are probably the nastiest to keep around, as both of them have a Chapter I that lets you exile something, and if youre doing that every single turn, your opponents are going to be in trouble
If the target creature is an illegal target when Waltz of Rage tries to resolve, it won't resolve and none of its effects will happen
Effects that switch a creature's power and toughness apply after all other effects, regardless of when those effects began to apply
Enter the Infinite I love this Gatecrash card, conceptually