Post-Mortem (dead) Ults

So in the immobile mage patch, we got a fun treat with annie ult chasing you down after death. However, I had a thought about another immobile mage that was just updated as well; Victor. Both ults are pretty similar, disregarding the single target vs aoe, theyre controllable spots of potential murder, yet when you die as Vic, your ult sorta just... sits there until it expires. I was curious as to why it wasnt updated to also chase after the nearest champion/lowest hp champion, until it expired. Is it solely because it cannot be killed as Tibbers can? Or was it just not seen as a viable design decision when immobile mages were going through updates?