just turn thornmails damage return into a more powerful windowed active

with the upcoming new rune system and especially keystones like "press the attack" that allows auto attackers to stack up infinite ad and "lethal tempo" that allows certain champions to break attack speed cap to up to 6 attacks per second, we need better ways to react to these abilities.

the way press the attack looks right now on the PBE it looks seriously overpowered to the point of sillyness.

make it like a 60 second cooldown active that actually returns some serious damage for a couple seconds to give us a way to be able to react to these absurd windows of power and force the enemy to momentarily switch target or to disengage.

lets look at the facts. thornmail is ass as its job, if youre not playing a tank like rammus or malphite, and the passive damage return has been nerfed to the point where the item is worse than before its changes at countering lifesteal despite the grievous wounds effect.

you dont want this version with the permanent damage return to be good anyway. so at least make it strong for short timed windows.