Changeling Trickster

[Orick]

In a recent campaign my Changeling Warlock killed a wounded NPC and disguised as him and has essentially taken over as him as far as the party knows. Its a bunch of fun and I want to do it again in another campaign and basically be a doppelganger and periodically kill people off and take over as them.

My question is: What is the best class for mimicking the actions of another?

I was thinking it might still be Warlock, but Bard and Cleric are also pretty good at doing this while still being pretty defensive. Any thoughts?

[DracoKnight]

In a recent campaign my Changeling Warlock killed a wounded NPC and disguised as him and has essentially taken over as him as far as the party knows. Its a bunch of fun and I want to do it again in another campaign and basically be a doppelganger and periodically kill people off and take over as them.

My question is: What is the best class for mimicking the actions of another?

I was thinking it might still be Warlock, but Bard and Cleric are also pretty good at doing this while still being pretty defensive. Any thoughts?

Changeling Assassin with the Actor feat. You will kick ass as an imposter.

EDIT: Take the Charlatan background and you have papers proving you are who you say you are.