To me that just seems completely useless, you get 11AP at lvl 18 for the cost of 3 mastery points. I tend to put mine in deadliness instead, giving me 2% crit chance. It is largely useless but it does allow me to score the odd last-hit on a minion i would otherwise miss.
Also kaiser I do like this early-game damage build idea. As veigar with my AP runes last game I was lvl 5 taking off a 1/5 of teemo's health each baleful strike, it was pretty effective! I often find that im focusing so hard on scoring every single last hit that I dont bother with harassing on veigar, especially as my mana regen only allows for 1 Q every 5-6 seconds or so, it seems a waste to use it on the enemy champ, but after 3 hits, teemo had had enough of trying to harass me
I was more free to last-hit in peace.
