There should be a harass starting item for solo laners

I was playing Sona support then tried her mid but noticed support had a LOT more damage early on, due to the extra damage from spellthief's.

So I thought, "There's an item for mana hungry champs, ring, aggressive marksmen, blade, farming marksmen, cull, and a greedy Mage item, seal. Why isn't there an item for assassins and mages who simply want more damage on top of their combo in exchange for long term survivability?"

It would be an item that provided no AP or AD, but instead drains additional HP upon damaging and can hold stacks, gaining one per several seconds. It would give champs sustain in trades like the other Doran's items but also increase their burst damage a lot in exchange for things like mana or consistent damage. Also, it's not possible to lifesteal off minions

Well, now that I think about it, Corrupting Potion might work but I think it's only good with DoT champs

EDIT: thx for downvote, really helpful and constructive.