Karthus' Ult

The following champions have, within their kit, some way to completely avoid Karthus' ult.

Several of these champions can extend immunity to others, or even to their whole team.

This doesn't even include champions with heals or shields, or damage reduction strong enough to foil Requiem:

many of which can also be extended to their teams.

If that's not enough, a number of items either completely or partially counter Requiem: These items cover all classes and lanes (Veil for tanks, Maw and Gage for ADCs and AD casters, Zhonya's for AP carries, Guardian Angel for whoever, and Face, Locket, and Crucible for supports).

TL;DR 23 of 123 (19%) champions have abilities that completely counter Karthus' ult. 6 of these (4%) can extend this immunity to others on their team. 12 others (10%) have heals or shields sufficient to more or less negate it 6 of these (4%) can also protect one or more allies. Every class of champions also has access to one or more items that either significantly reduce or completely avoid Requiem's effects, and the three for supports can also protect their team.

Karthus' ultimate also has the longest channel time of any ability in the game (Fiddlesticks' Drain and Yi's Mediate can last longer, but also have immediate and continuous effects), the highest base mana cost, and the longest cooldown at all ranks of any ability (at level one, it's on par with most summoner spells).

That said, I love playing as Karthus: he's super fun, and I think that his kit is super great on the whole. I also don't think that Karthus is terribly weak right now, despite these issues. I think that his ult is a little too far on the reliability--power spectrum: in order to account for the inordinate power of the success case, that power has to be hidden behind an enormous number of obstacles. If you can counter Karthus' ult, it's useless, but if you can't, it's devastating. The dichotomy that this creates makes it less about what you're doing and more about who you're playing, which isn't fun. Nobody likes to win or lose in champion select.

At least for me, the fantasy of Karthus' ult is raining death upon my enemies from afar: looming death and so on. Too often, though, I just end up using it basically in the same way as my E: when people blow all their cooldowns in a teamfight, I throw it out during my passive for some extra damage. It's simply too inconsistent if you don't. It doesn't have to be that way, though. What if the spooky column applied grievous wounds or stopped healing altogether? What if it became single target, but punched through untargetability like Soraka's ult or reset on kill like Darius'? What if it ignored shields or gained an execute? Karthus is the first champion I bought, and I just want the best for my favorite headbanging death ghost.