The ninjutsu ability can be activated during the declare blockers step, combat damage step, or end of combat step
I mean, my card pool is deep, Ive got all the dual lands, and Ive built dozens and dozens and dozens of decks since becoming an early adopter of the format
Its in the same vein as Whisperer of the Wilds, although Ruby has an attack trigger rather than giving you 2 mana
Mutated creatures are treated as a single entity so if a mutated creature you control is bounced to your hand, all the cards in the pile go into your hand separately all at once
While not an auto-include in every deck, it shines in Commander strategies that go wide with creatures or focus on counters, such as Hardened Scales or token-heavy builds
Aristocrat decks are also usually Graveyard decks so using blood tokens to discard Reanimate targets seems sweet