On hit healing that stacks basically depending on how far ahead you are isn't right on a dps item

It leads to the drain tank problem that RIOT is trying to fix in warwick's rework.

However, On hit healing isn't a bad gameplay mechanism inherently. It works fine for dorans blade and aatrox for example, and although it isn't right on feral flare it could still be good on an item.

It would be nice to have on hit healing as an option, but it should be gated by how much damage you stack, otherwise you get people who just build on hit healing and attack speed (or have attack speed in their kit already) and then build straight tank and abuse the constant healing over time to make them not only tankier than they would otherwise be even with a pure tank build, but also do more damage and be more of an influence.

It would need to be gated so that it is powerful on champions who take the most risk in using it. That means more powerful on melee champs in general, and more powerful on melee champions that tend to build on the squishier side.

I'd probably have it set up to be X on hit healing, then 2 * X for melee champions and have X scale with attack damage, making it more effective for squishier dudes that devote a lot of their build to damage.

But if we make it scale with attack damage doesn't that just make it the same as lifesteal? Well no. Critical strikes aren't going to increase the value of the on hit healing but they would increase the value of lifesteal. Enemy armor diminishes the value of lifesteal, but it doesn't diminish the value of on hit healing. Different things for different purposes.

Lifesteal is a very targeted form of healing that works well against a particular kind of target. On hit healing is just what its name says it is. I wouldn't be put off if we had more on hit healing items, or if we replaced some of the lifesteal passives on items with on hit passives.

Like bloodthirster for example.