I can't recall a game where Garens Villain mechanic has made a difference
I can't recall ever seeing it against my opponent in lane phase even when I'm getting perma bullied by Darius, Sion, Teemo or GP is barrel zoning and Klepto Q farming me to hyper carry status. Can't really think if anything more villain like than these lane phases ;)
It could be on the enemy jungler too but I'd never see it and even if he ganks it would be pointless because I cant make use of it 2 Vs 1 before I get instant gibbed. :((
Its possible it could be on the enemy ADC but I would need TP to get to them. If I did this my tower would be lost giving up 500g to an opponent who is likely Nasus or GP and if the enemy ADC is the villain anyway then they're fed in which case GG it's over regardless. I won't be able to close any gap to them before I'm burst down.
In a very rare instance we may reach late game as a team but like I said I can't actually recall seeing the villain mark much, if ever in a late game TF. And regardless I'm going for the ADC 90% of the time anyway because of the very real and present danger they present.
What I'm basically saying is it's pointless having it. I'm not even saying it's bad. I'm saying it's of no use at all. Thematically it sounds nice but in practice it's utterly irrelevant.