Originally Posted by Anachronity
On his ultimate: Slow is not the same as knockup, knockup is much stronger, Harin also has to channel for 1 less second, which can make a huge difference.
More important is the fact that Harin is a much larger influence on team fights than Nunu without their respective ultimates. Harin is also naturally more tanky than Nunu and has other hard CC than his ultimate, which Nunu lacks.
Like I said at the end of my post, none of his abilities are overpowered by themselves. If Nunu had his ultimate transplanted with Harin's, he'd be approximately the same as he is now. Harin has too much damage, tankiness, CC, and versatility for one champion.
While that's a valid concern, I'd say damage is stronger than CC of any variety. Knockup lasts for, at max, a second. It's basically a stun that Tenacity can't reduce (Due to it being gravity.). Also keep in mind that Nunu can, again, release it early for less, but still potent damage. Harin has to go through the full channel to deal his damage, and is very vulnerable to interrupts. The only other champions who have such a long channel to deal damage are Caitlyn (Who then snipes someone for pretty hefty damage at crazy range), Pantheon (Who teleports to anywhere), Karthus (Who explodes everyone regardless of where they are), and TF (Again, teleports anywhere.) Every other channel can be canceled mid-cast for reduced effect. While damage and knockup are indeed potent, Harin is incredibly vulnerable while casting and even at max rank with max cooldown reduction, it's another minute before he gets a second shot.
Yes, his kit is geared more towards disruption and the like. That's his shtick. He's all about taking a lot of hits and either keeping the enemy away from his team, or right in the middle of it. Nunu is more of a jungling dude, given he has SMITE on his freaking Q and the highest base health in the game. While Harin is most certainly going to be building tanky, Nunu doesn't even have to to be scary.
One thing I will admit to screwing up on is that technically his abilities should scale on bonus
HP rather than max. I claim full responsibility for that derp-up. However, I feel that overall, his very long cooldowns and awkward builds balance out his relatively potent damage and disruption output. He's got a lot of potent spells, but he can't cast them nearly as frequently enough as to carry a team. He's much more of a mage/fighter than a mage/carry.