Twice I fought him and my ult did nothing. He did have maws but with 15--20% hp it should deal some damage right? I forget how the second one went but the first attempt he took zero damage. I recorded it but the match was long and rather not dig it up.
thinking man2 votes[deleted]
XElement1 votesSo even though Panth had about 15% hp; Maws can completley block my finisher move?
Rebonack2 votesDownvoted for asking a serious question?
Stay classy, Boards.
Anywho, answer is no. Panth's Innate only blocks basic attacks, tower pews, and OnNextHit type things. Garen's Ult is none of those.
XElement2 votesI downvoted myself. I am old fashion. I do not like how by default they give me a like. So I took it away...I suppose that is odd though so I will give it back.
EndlessSorcerer2 votesPantheon bought a 
at 8 minutes into the game, which will stop the magic damage Garen's ultimate does. Since he wasn't your lane opponent, I wouldn't worry about countering it and just build normally and use your ultimate on someone else.
I would recommend rushing Brtualizer into Sunfire Cape when your opponent decides to rush Hexdrinker against you as Garen. The Sunfire Cape aura will proc the Hexdrinker shield so it won't be available to block your ultimate and you have AD and Armor Pen to pushing their lack of armor.