Heap Doll

[ELLERfeller]

Say  {Kozilek, Butcher of Truth} is killed and sent to the graveyard, could I activate  {Heap Doll} in response and exile him? Or will his triggered ability resolve first and shuffle him back into the library?

[Kaylesh]

Say  {Kozilek, Butcher of Truth} is killed and sent to the graveyard, could I activate  {Heap Doll} in response and exile him? Or will his triggered ability resolve first and shuffle him back into the library?

Once Kozi hits the graveyard, his ability triggers. You can respond to it by exiling Kozi. He will be in exile once his ability resolves, which shuffles the rest of the graveyard in the library. (Long story short: you can exile him, but that will not counter his ability.)

[ELLERfeller]

Okay cool that makes me happy!