Have to figure out how to prevent abuse.
Easy: Amused has an ability X whose effect is temporarily changed to an adjacent creature's ability each turn. By adopting the effects of adjacent creature's ability, any effects that include "lobotomize self", e.g., lycanthropy, deja vu, will remove ability X.
If this creatures ability is to change every turn, what is to stop it from simply grabbing the lycanthropy ability again?
Two Ways:
1. Let "amused" be an active ability that, each turn, changes its on-click effect (but not its continuous effect) to blahblah's ability effect.
For example, if it adopts the "devour" effect from a Scarab, it's on-click effect will change to "kill target creature with less HP and gain +1/+1", but its continuous effect will still change its on-click effect each turn.
Alternatively, if it adopts the "deja vu" effect from Deja Vu, its on-click effect will change to "generate a copy of of this creature [and lose this ability]". Thus, if you activate "amused" (or "deja vu" if you want it to be able to change the ability name), you'll lose "this ability", which is the entire effect of "amused", including its continuous effect that adopts abilities each turn.
2. Let "amused" be a passive ability that, each turn, adopts a new active ability if and only if it currently has an active ability. I don't think this one needs any explanation, because the cases are basically the same as above.
The only problem with a passive ability is that if you can give it a new ability (Butterfly Effect, Luciferin, Liquid Shadow, Mitosis), it'll in a way restart "amused" even though it thematically shouldn't (in my opinion).
