Let's give a small change to Karthus's Q

I was thinking earlier about Randuin's omen and how it now blocks about %10 - %20 ALL types crit damage including Anivia's E (Add Frostbite) and Karthus's Single Target Q, and I was thinking about how neither of them will really be viable with all the juggernauts lumbering around the place like they own it. (though to be honest, it's probably the case anyway) So I thought that maybe they could get a small change to their extra damage components, especially for Karthus.

My proposition is: Instead of Karthus doing x2 damage on a single target hit, have him do his regular damage, but instead also do the same damage as TRUE damage. This way, Karthus players will get more incentive to single target Q, he'll be able to take down the tanks easier, and he might even be a viable pick in games for the Dragon/Baron Pressure (since he's already one of the best takers of Drag/Baron any way.)

This could also work for Anivia, where instead her E does the same as the proposed Karthus Q, not sure how it would work out though, I've never really played Anivia myself much.