Don't have the save right now, so I'll just explain it over my current save game
Red X - must have
Pink X - good to have
Basically you need a lot of endurance, so that Karryn can take more dicking before cumming.
Some willpower to spam 'healing thoughts' (restore energy)
And some dexterity because it increases the pleasure damage you deal to the enemies.
Also, get the items that give you more energy, especially the bracelet that gives you energy regen.
Karryn starts as a pure girl, so it may be hard to transition into a slut. If you're not experienced, I'd recommend picking up fights at the bar - where the enemies are the strongest on lvl1 - and just getting repeatedly defeated to unlock some passives and sex skills and be able to fight the prisoners with your body as soon as you can.
If you want to be an actual cumdump later on and just skip your turns while they're fucking you, you can ignore stamina and revitalize edicts.
!!!Nerd talk below!!!