But you can also just not do any of that and keep your non-legendary Isamaru? Okay.

Edit: I was originally thinking that the “return another creature” part was optional, but it isn’t. If you have any other creatures, you have to return one. That means this probably isn’t an auto-include in aggro. Might be better suited for combining with creatures that have ETB abilities, such as Tranquil Frillback.