There's a lot of characters but jos skins always seem to go to Anna and Roy, because they're unlocked by default I guess? But that means all of your skins are stuck to a couple of characters, and then you're only choosing to see one skin at a time. At least for me, needing to manually switch skins means I end up sticking to one and never see most of this art. Could characters have checkboxes on the selection screen that makes them switch to a random skin and palette after using a portal (and/or on loading the game, but portal seems more fun)? I expect it'd increase sales too because it'd stop people from feeling like a skin would never get used.
For the same reasons, it'd also be nice to have another checkbox to randomize the characters themselves - players on the rare character-specific quests could just disable it for a bit.
For holiday buffs, they could either passively be always-on for the duration if you own the active skins (which would be cool in itself), or again players could disable randomization for it.
edit: Actually dark divinities could be used to turn it on and off I guess, like one for random skin/palette and one for random character. Then there's no need for interface changes.
— Kristof, Purchase in the Jewels of Soul tab for 75 Jewels of Soul
The only character with a bonus. The bonus gives +15% CpS during any December.