Honestly as a porn consumer LoL is a shitshow. "Characters" have so many skins, several of them more porn-popular than the "canon" design (looking at you bunny Riven...) that search tags become nigh useless and few if any sites care to make separate tags. Doesn't help that characters get redesigned and rewritten all the time either, there's no point in getting invested in canon lore and personal headcanon/fanfics won't gain as much traction. By comparison Overwatch skins don't seem to have nearly as much representation, you see the occasional pink Mercy but even directly searching for Starcraft doesn't return many results using the Widowmaker skins.
I have seen a few games though and with decent variety too. An OC-story-driven VN series called Summoner's Quest IIRC (oh yeah, remember when those were canon?
), a plotless Flash game called Fuck Your Champion, a Lux+Kat+Irelia femdom RPGM game and I swear
The Wind's Disciple used to have blonde Janna in the screenshots.