Everyone's talking about Yi+Taric as the new Yi+Kayle cheese. I think Master Yi will never be a healthy champion with the current Guinsoo's Rageblade with the way his passive currently works.
The second hit of his passive counts as the first hit towards the next double strike, and since his passive counter is considered on-hit, this means with a fully stacked guinsoo, he'll be double-striking every other attack. So in 4 attacks, he'll have 6 hits, meaning with guinsoo he applies on-hit affects 9 times. Any other champion will apply on-hits only 6 times in 4 attacks with guinsoo. In other words, Master Yi is doing 50% more on-hits.
That's his E's true damage, Bloodrazor's 4% max health as physical damage, Guinsoo's own on-hit (which imo is overtuned. it's 5=10% bonus AD and 5=10% AP, but since each guinsoo stack gives additional bonus AD/AP this at 6 stacks it's 12.4% bonus AD and 12.4 AP), if Taric buys ardent censer then there's 5-20 extra magic damage on-hit, and if you haven't already forfeited, Yi will be getting Botrk so that 8% current health on-hit.
Guinsoo is pretty much the reason Kog'maw's W was nerfed and more recently Varus' W on-hit. The "extra on-hit" passive was introduced way back in like S5 on Sated Devourer and it's been a balance nightmare ever since. I think it's time for Riot to get rid of it so champions can have innate on-hits that aren't nerfed to hell.
If not they should at least remove the guinsoo feedback loop with Yi's doublestrike.
They could change it so the on-hits applied by doublestrike's second hit do half damage (except Yi's E since it's true damage). It would be a smaller nerf than he needs right now but it would at least be something.