Greetings all, nice to be here.
Similarly to Gobnard, here's a rundown of Guiverni's skills and abilities:
Sneak, with or without invisibility
Lie through his teeth, also in combat
Know when others lie through their teeth
Do cartwheels and other acrobatic stunts
Read minds, make people forget and communicate telepatically
Do those mind things on masses and on undead
See dead people
Change shape to any humanoid
Store things in the folds between space
Store memories in the folds of his mind
Teleport all over the place and bring you with him
The noble art of (sky)boxing (he can physically box, though more style than substance, and has destructive blasts for bludgeoning damage)
And if all else fails he can always stick you with the pointy end of his sword or shoot his pistol at you. But those are desperate times.