What would Garen need out of a rework?

so as far as i know, he's still intended to be the 'anti-carry' assassin-y juggernaut. he trades sustained damage for spin burst and execution power with the villain mechanic. since mira keeps making threads shilling against Garen, i figure i should make one too, since i'll be making another thread for garen like i did with voli/mord before to mass critical acclaim xd

so my questions are thus;

An assassin requires some means to reliably reach their targets; the villain system compensates Garen's current lack of reliability for this by giving him bonus dmg and true damage to a target, as well as doing more damage to isolated targets on his spin. if this mechanic is removed, and assuming that we want Garen to be the assassin of the group, how do we give him the means to reliably reach and kill important targets while still keeping him with the immobility a juggernaut is supposed to have?

If we instead shift Garen to be more of a heavy duelist/skirmisher-type of guy, how do we make him different from other juggernauts like Nasus, Trundle, Darius, etc. beyond most of his DPS being tied to an aoe spell? What would set him apart in that case?

What major mechanics can feasibly be added to a melee champion with no means of extending his sphere of influence, no range, and no mobility? The same problem exists for at current; their kits are inherently extremely limited, so it makes sense that they're fairly simple in return, but they are quickly being phased out by a game that's evolving without them. Do we rework them to have some form of extending their threat range, and can their identity be preserved if that happens?

Should we replace his passive with something that rewards aggressive play? It's a personal opinion here, but if there's one thing I hate that's not mages, it's playing like a bitch (mages); and Garen's passive makes me do exactly that. Is it offensive enough to warrant change?