Vili is an Arch Imp, which you will run into after you get the sigil of allure, Go back, go to the imp den, rush into the den and successfully beat them all. There will be an open passageway, follow it and you'll run into a woman with HUGE tits. After meeting her (and if you choose to fight her, you get a funny scene), you have the chance to play with Vili, if you accept her offer. Gotta be somewhat powerful if you accept the challenge! If you've beaten Sofia's three challenges you should be plenty powerful enough to face Vili's challenge!
You can also just rush into the imp den and fight them. Once you win you will have an option to enter a hidden door. In previous versions you could do this on your first time in the dungeon but in newer saves you should have to complete it first.
My goofy is a level 98 with the highest luck (100 ish)
I thought a CRIT build would be funny I was wrong crits are a pigment of your imagination
Crit relies on luck and technique stats you can also learn sense weakness which along with other perks can get you up to 99% crit rate
Imo still pretty funny stacking buffs / debuffs to see big numbers
