He got a massive overNERF in 6.4, the very next patch after he got buffed, that dropped his winrate to 47% from 52%, then got a MEGANERF exactly 5 patches after that in 6.9 when they removed Devourer and gutted Rageblade, which dropped his win rate to 40% from 47%.
Then he got some health buffs in patch 6.12, which along with nerfs to some of his biggest counter champions slowly allowed him to raise his win rate to 49% over the rest of Season 6, until Fervor got buffed recently in 7.4, which put him at about 51%.
So yeah, it's a good thing you stopped playing him, because he was basically in the shitter for almost the entirety of Season 6 because of that damn "buff" in patch 6.3.