I think SalmonGod is a pretty cool guy, eh tanks Karthus and doesn't afraid of anything.
Not me. Mundo!
Tell me, how often are you against a Karthus?
Not terribly often, but enough total occurances to know how it works out.
Me as a player who once had Karthus as his Main champ knows how he works. He hasn't been changed pretty much at all, so I haven't had problems with it.
The bomb deals heavy damage on low cooldown, has low mana cost. Very, very good harassing ability. But it deals double damage if he hits you alone: In a 1 vs 1 he will deal huge amount of damage.
Wall of pain reduces your armor and magic resistance by a very large bit, so he becomes even more dangerous. If he rolls with Lichbane, have fun. Also, huge-ass slow.
Rylai's Scepter + Defile = Don't escape from him at all, and he hits all of his bombs since you're too slow to dodge 'em.
And if you Do manage to bail out of the situation, LOL REQUIEMED :dddddd
Most karthuses are known for killstealing with R early on, and then becoming unstoppable with the godly damage on it once fed: Real Karthuses however, always hit their target with Lay Waste, and because they're pr0s with Karthus, they place the bombs so you receive double dmg.
His ganks, godlike. THe slows and damage kill many un-aware enemies, and with his R it is very easy to catch them even if they escape to the tower.
Did I mention that Rabadon + 5 Archangel's Staves make him a real god?
Now, did you get any new info of him or did I make this post for nothing D: