Should I main Karthus

do you like playing karthus?

Yup

he is pretty boring imo

but it's your decision he is strong when played right

He loses a great deal of lane matchups BUT exhaust karthus sometimes surprises people to cheese early and if you make it to late game a q and an r will kill an enemy adc or apc. If you can survive most lanes unkilled I'd say go for it

thx

Another Karthus main speaking here:

Karthus IMO is fun to play if you like getting doubles and triples with the ult. Here's how most lanes go for Karthus.

Mid - if your opponent is a farming mage, you might get away with just a couple trades. Also I suggest Auto-Banning Fizz for mid lane otherwise YER GONNA HAVE A BAD TIME

JG - Slightly harder to do, but if you're JG that means you could get a mid with hard CC which helps landing Q's a lot easier. Just need to worry about early invades and counter junglers. On that note, Ban Lee Sin if you want to JG otherwise YER GONNA HAVE A BAD TIME.

Top - I don't really play this lane nearly as often, but if you're against a melee top, that might make things a bit better for you since they have to get close whereas you can just kite. Dunno who to ban tho. Sry :/

I don't play Support or ADC Karthus so I can't help you there, but maybe Karthus's Damage and W slow might prove useful as a support maybe.