Riot should add 'multihit'(and use it to bring back spell vamp and help balance bruisers and items!)

So, we can see on the PBE with the upcoming morgana change that Riot is already moving to the idea of 'skillvamp' (SV) to replace the old spellvamp as seen also on Ravenous Hunter (which works with almost any skill except for a few auto-attack enhancers like Draven Q with the exceptions I believe being things that work with life steal). We're also seeing an issue with assassins, more traditional ad bruisers, and more tank-like ap bruisers (e.g. gragas) where botlane marksman like Varus+lethality and skirmishers like Ekko+ibg/sunfire are leading to both items and runes being balanced to the point that both the coutner-meta and meta traditional toplaners aren't happy (well, okay, teemo mains maybe, but I've seen rumble and kennen mains complaining alongside the riven and renekton mains) while junglers just stop playing half their pool entirely because of nerfs to items/runes regularly killing entire playstyles (personally I'm not touching jungle ekko, malz, maokai, or nunu right now and only reluctantly playing gragas). But I think multihit would change all of this!

Ffor balance purposes, multihit could be a stat on certain items (maybe runes) that makes it so all non-self-targetted skills and onhits (but not crits or aa's in general) have a chance to do up to two multihit procs which are, say, 50% more effective each (with the chance of things which don't make sense like 3-hit passives being 1 shot at double proc) with the special bonus rule to keep it from scaling too hard that an ability can never mulithit twice in a row (so you can multihit twice on one hit, but the next hit won't multihit from the same ability or on-hit no matter what). A stat like this is immediately less valuable to Asasssins's and most ADC's at first glance so it separates out from lethality. At the same time, it offers an alternative offensive stats for tankier champions which includes bruisers. If done right, multihit vs lethality would be the key to a lot of ad casters, but also a great way to make cheap bruiser items that work for both ad and ap bruisers without necessarily creating a stat that would be as good on someone like, say, Ekko (because his shield and healing scale off of AP and multihit would not work on him because they are self targeted). For an example, the current Guinsoo's could be modified to give 50% multihit in exchange for less bonus stats per stack to keep it balanced (so on hits would proc 100% of the time twice every other hit when relevant, but other things coudl multihit making it even stronger hence the need for a slight nerf).

But, it could also do a lot more than that by being an identifier for types of attacks - multihits. After all, we've already got pseudo multi-hit with Guinsoo's and while WoW used it effectively during Warlords of Draenor even if later deciding not to (and more creative uses of crit which we recently started seeing in LoL with Xayah's E being an ability that scales straight off of crit which is a staple in WoW's balancing). This works because a variety of things can be made to count as multihits for balancing purposes e.g. Akali's passive, q, R while making it so that something like the new skillvamp (on morgana on the PBE and on Ravenous Hunter on live) are, say, 1/5th as effective on multihits. Then most champs building omnivamp wouldn't want a skillvamp item, but also champs like vlad wouldn't be completely broken as his Q and E could both be counted as multihit! In fact, the classification of multi-hit used to exist for the purposes of Rylai's categorization. On top of that, actual abilities which multihit could have their multihits provide reduced healing or effects than the main ability/attack in this case when they do proc.

Anyways, Thanks for reading and please feel free to provide feedback!