Renekton? Really?
Jax? He's good now, but not overwhelming.
Lucian and Ezreal are both good for different reasons. They were among a select few champions to not be nerfed itemization-wise by the ADC item changes. Maybe a little, but not enough to make them bad. And, to be fair, Ezreal abuses EVERYTHING to it's maximum.
Master Yi probably the only champion here that suddenly got a bump in power by this item being introduced and easily seen why. It gives CDR, a stat previously pretty hard to get in large quantity on him, fixes any mana issues he might have, and synergizes perfectly with his ultimate and kit. Master Yi has suddenly become a champion that a decent number of people fear, especially people who don't know how to handle him. However, if we look at Master Yi on any data site... his numbers are actually average at best. His play rate might have went up, but his win rate has only increased slightly. The biggest increase was near Bronze, where he got a 3% increase in win rate. The lowest was near Platinum, where his win rate went from 49% to 50%.
What I'm saying is the only people who might suddenly think Yi is the best champion this patch are typically a lot lower in skill level, and that's not an insult. It's just stating what's shown by data. Yi is causing issues in lower ELOs and that might need to be addressed somehow, but it's certainly not a reason to nerf the item itself. If only ONE champion abuses an item, nerf the champion, not the item. (I'm looking at you too Ezreal!)
(probably)
was made melee only because ADC's "abused it"
