Gragas's W is the most awkward ability in the game
Riot, please fix this ability. The rest of Gragas's bruiser rework is fine. He's otherwise an engaging and fun champion to play. But his W is a nightmare to try to make the most of.
The bruiser rework loaded a huge portion of Gragas's power into his W. It's his main source of sustained damage and tankiness.
Gragas channels for 1 second, and gains 2.5 second of damage reduction. The incredibly short duration means any smart player can simply hold onto their big cooldowns for 2 seconds before dumping them on Grag. Gragas isn't even able to fight back for almost half the duration of the damage reduction.
No matter what you do, it feels like the ability is punishing you. If you use it once a fight/duel has already broken out, you are punished (it can be interrupted if they have any CC, and you are taking damage while unable to fight back). If you use it before you go in, you're broadcasting to your opponent: "hey I'm about to body slam you, it might be time to back up behind your minions." Drinking his beer can literally only mean one thing--that he is about to go in. Additionally, using it before you go in wastes a substantial portion of the already laughably short duration. By the time you've body slammed into your opponent, 2/3 of the duration is probably already gone.
At max level, the ability has a 4 second cooldown. With 0% cdr, you have to spend 25% of a fight channeling in order to use it whenever its up. With 40% cdr, you have to spend over 40% of a fight channeling. Of course, if you don't use it whenever it's up, you are sacrificing a huge portion of your sustained damage and your main source of innate tankiness. Again--no matter what you do, it feels like the ability is punishing you.
I don't know that Gragas is necessarily weak right now. This isn't a "buff Gragas" thread. All I'm saying is that it is fundamentally not fun to spend 25+% of every fight locked out of your abilities and auto attacks.
The point of the rework was to make him a tanky front line bruiser. It makes no sense to force a tanky front line bruiser to channel this often. It feels unbelievably awkward to spend so much time channeling while hanging out in melee range of the enemy team.
TL;DR: Gragas's W is incredibly strong, but incredibly awkward to use. If it didn't have a channel time, it would probably be overpowered. Making an ability incredibly awkward to use is a frustrating way to gate it's power