No one really complains about Gnar getting 14% max health damage
That is potentially on a 4s CD but when Sejuani has it people go nuts :O Note: Everything here is theoretical because Sejuani is perma banned and I rarely get to see what happens in actual game play.
"Hey don't compare different champions!" Okay let's see...
First off outside of her icebreaker passive Sejuani has really low damage, her whole kit has lower damage compared to before so although she has 20% max health damage it's like okay... 20% on say a squishy usually is around 350-400 damage, which is usually around around 1/5 of a squishy healthbar so that's quite a bit. However you need the 4 stacks and need to proc icebreaker for it which would take around 3-4s if Sejuani is by herself and than afterwards if you wanted to proc on the same target again you would have to wait ~14s. With an ally you still would need around ~11s to get a normal proc off again. So 1/5 of your health and than Sejuani is kinda outta options here because the rest of her kit is really lacking, if the squishy has any sort of support or is able to fend for themselves Sejuani won't be doing much I reckon.
Gnar on the other hand has range and has his 14% max health damage on about a 4s CD. So off the bat he will have more potential to get off more % max health damage than Sejuani. Sejuani may be able to get it right away on the engage but afterwards Gnar just does more, while being squishier. I think the main point is Gnar is able to get off more max health damage than Sejuani ever could but people don't really complain about it :O
The gray area is whether or not a tank should have that much damage in the first place cause that often leads to unsatisfying gameplay stuff. As mentioned earlier Sejuani will always have a ~11s CD on her 20% max health damage which means she's not doing that much damage overall cause of the rest of her weak kit. In the end, other tanks probably deal the same amount of damage that Sejuani does just over time rather than all at once.
My main point is stop banning Sejuani so I can see how she works please.

[zombie-nunu-tears]
Sejuani has kinda fallen in discussion on the boards but she is still getting perma banned and I've only seen her a total of maybe 5 times since the patch came out! I can't even have an proper opinion on how good she is.
I'm tired please be gentle.

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