Magic or armor pen? Help please, and thanks.

I use Apen because Sheen matched with E + Apen makes for good damage. Granted probably 50% of his damage comes from R and Q but those are instant dmg whereas you will be melee with W and E most the time. E will be up 2x before Q or R will be up anyways so utilize it.

You want armor penetration. The problem with magpen is you're doing virtually no magic damage while your ultimate is on cooldown, and seriously, your fist does WAY more than that silly grabber. The only reason I use magpen is because I'm too cheap to get a full set of Apen runes. Maybe someday when I'm not so irresponsible...

Ya even as ap... Armor pen, your ap boost lichbanes physical damage and even full ap... Punch is your main damage