League of Legends XXXII: Cupcakes and Kittens and Squirrels. Oh my!

[Eldariel]

J4 is probably underplayed because of other champions. His playstyle is really similar to a combination of Lee Sin's and Alistar's, and I think that most people who would jungle J4 just play one of those two champions isntead.

He's underplayed 'cause he got nerfed and people kinda stopped playing him. It's the same story as with e.g. Orianna; still incredibly strong but just not played as much.

He has more damage than Alistar (mostly Martial Cadence) and more CC than Lee Sin; he falls squarely between the two as an equally viable pick with solid L2 ganks and solid clear and ridiculous free stats.

Well, Alistar's entire kit is or has been broken, and I don't think that anything but Amumu's Q/R really compare. Alistar has/had the best base stats, the best level 2 ganks, the strongest type of CC, a stupidly powerful ultimate, some of the best initiation, and the most mana efficient heal in the game. He was literally AP Sion with more damage, more utility, twice as much CC, and almost four times as much survivability.

Amumu potentially has the best teamfighting ult in the game, but it's held back by being a PBAoE with a gigantic cooldown.

The equivalence I'm drawing is that people kinda seem to want for him to be bad (see also Ezreal months back when junglers decided to start talking crap about him; suddenly he's the third most picked AD in Hannover with better win percentage than both Corki and Kog'Maw) and come up with a ton of silly theorycraft about why that's the case and then it becomes upon the truth itself. Like, he has clear weaknesses in early fighting but I don't feel those weaknesses are really big enough to make him unviable even on tournament level; just currently not preferred due to the types of comps top teams like to run.

This is pretty much what happened to Alistar for a massive amount of time too; he was always good but people began pretending his cooldowns are too long and that other champs fill his role better and that he isn't worth picking. Had this belief not been so widespread chances are he might've been found already back in WCG 2010 or so; AP Alistar was practically overpowered back then and support Alistar was as good as ever.

Basically, I'm just saying the collective has a track record of being horribly wrong about champion viability (see also e.g. Evelynn, Jax, Kayle, Akali and...yeah, about 50% of the champion-base).