Undertow's ( Q ) slow now fades over time. no biggie
Vicious Strikes ( W ) cooldown increased from 12 to 16 seconds. kinda hurts.
Ragnarok (R) no longer grants passive Armor Penetration and instead grants 10/20/30armor pen while Ragnarok is active. understand the need to nerf the passive, but that is not very well thought out. his (R) needs something added if the passive is gone. the burst it provides and cc imunity isnt good enough for an ult. as soon as you pop it in a teamfight you are focused and die before ever reaching the adc anyway. bad balance team, bad.

good bye Olaf, its been a pleasure knowing you. every champ dies, but not every champ truly lives. you sir, have had a helluva life and a great run. now off to obscurity with you. tell Trundle I said hello.

Figures they'd nerf Olaf, and give Kat's ult more power. Good job Riot, you nerfed a balanced character, and buffed an op one. Again.

Looks like I need to find a new champ to main..

Olaf wasn't completely balanced. His kit just got too big with Warmog's. If they nerfed Warmog's, that'd basically nerf the entire champion list.

But I REALLY don't think the nerf to Undertow was necessary. Really? What's the point of the slow if you can't even chase anyone now? I heard about these changes on the PBE, but didn't know that there would be this many.

Kinda agree on Undertow. Rather hurts his viability as a jungler because it makes his ganks less effective (not hurting his clear time at all).

I can live with the undertow change.

I dislike the change to his ult. I mean really I like Olaf's ult but I wanna be good without being in Man Mode.

I really don't like the axe nerf since it basically kills his jungle. I don't mind the increased W cooldown, but the passive armor pen loss really hurts. This, along with the warmogs nerf, probably takes him down in viability a bit. Sure, he was strong, but this is a really hard nerf.

Because Olaf never picks up the axe while chasing amrite.

Olaf is one of if not the best chaser between his Q and his R, this nerf is pretty damn irrelevent.

perhaps you overlooked the part about removing the passive from his ult?
removing it altogether without giving something in place of it is too harsh, and its going to kill him.

using his R for burst to burn in a 1v1 works great. using his R in a teamfight is a joke. any opponent with the most cursory knowledge of Olaf is going to focus you down before you get anywhere near a squishy. the whole point to his R was the passive. now its gone and we are left with a useless ult, except to use as a CC immunity for escapes.

an Olaf nerf isn't really needed...what is needed is this new "meta" now that all these champs just stack 1 damage item and then rest health....darius, Olaf, Cho gath, Singed, i can go on and on. Once they stack health...it's GG for the team they are playing against. The HEALTH items need to be nerfed.. I'm glad Warmogs got nerfed...even though the passive doesn't stack +1000 health kills if you have 3-4 warmogs on a Shen..or darius...or even an Olaf which i have seen.

Well, if the team is smart they focus you down once you pop Ragnarok... but Olaf takes a lot to kill, and he can't be CC'ed, which makes killing him harder. And all this time, Olaf's team is wrecking the other team while they try to focus a bruiser-tank. These nerfs should hopefully tone down his lane phase and ability to fight and win in disadvantaged fights. Olaf needs to be kill-able before he gets to the carry (not too farmed/fed).