new champ idea. vampire monster hunter

you know how league doesn't have any true vampire champions well the other day i was thinking about an old game i used to play called darkwatch. it gave me the idea for a vampire champion with a similar ability like where he can choose to either be devine and except the light or indulge his vampiric side. give him a passive like he uses some of his blood in his abilities witch infect enemies with vampire plague and give him an ultimate like devine light or something that when used on a champions with vampire plague it ignites and slows them. this is all i could come up with so far its just an idea i wanted to share with people cause i thought it was cool