You can’t currently create new (or modify existing) AI in UEFN. This is something that is being worked on (Saxs mentioned this in the SypherPK interview last night).
You can add the SkeletalMesh to the level though, and use Sequencer to play animations, triggered from Verse. This was the general approach take for the boss fight in the GDC demo, but that was very complex (involving ControlRig as well)!