Here is what I know:
- When a kohen gadol dies we replace him. In fact we've got a replacement kohen gadol waiting in the wings on yom kippur just in case
- Any kohen who becomes kohen gadol gets anointed with oil
- There are 5 types of things which are forbidden on yom kippur including anointing and bathing (Yoma 8:1)
- Someone who already is a kohen gadol, on yom kippur must immerse in a mikvah
My question is if a kohen becomes a kohen gadol on yom kippur does he get anointed with oil or not?