I remember, a long time ago, the reason karth's ult was nerfed in cd was because it provided "way too much" pressure.
Jungle Karthus true terror: Ganks all the lanes at once.
Now, you get champions like kindred, bard and taric who have ults (on a much less lower cd) which can simply negate karth's ult,
Can, but they aren't reliably going to do so.
Karthus ult does hit all 5 opposing champions, and throughout most of the game all 5 aren't going to be right on top of one-another.
and this is without including all the myriad of other champions and items like soraka and hourglass.
While such mechanics can seriously mess with Karthus's ultimate, it's worth noting that timing is literally the only skill necessary in using Karthus's ult correctly.
With global range you don't need to be in a specific place to use it.
With point-click accuracy that doesn't even require point-click there's no skill involved in aiming it.
With striking all 5 opponents there's no skill required in targeting.
The only skill necessary with Karthus's ultimate is timing it correctly.
It can be timed around CDs of things that can counter it.
Not only that, but for the mage update there was absolutely nothing offered to karth to compensate for his weak early game and slightly above average late game.
Karthus's late game isn't slightly above average, it's absurdly strong. You just need to do well early/mid to get the late-game going.
His sustained-DPS, 1v5 potential, resilience against focus, team-fight prowess, and scaling all place him as one of the most terrifying champions in late-game.
