subaru x reinhard BUT make it toxic yaoi (ayamatsu if)
basically there are multiple what if stories in re zero and the first one (pride if, aka ayamatsu) makes subaru so much worse than in canon and hes evil and he kills everyone and he hates reinhard bc hes jealous of him... i dont want to go into spoilers but yeah they have a very interesting dynamic and i think they could be really gay for each other stares at them