That just happened. Negative ap is a thing

Somehow I don't really like the new changes to Mordekaiser, it feels like I deal less damage...

Jokes aside, I was running ad runes and tank masteries on Mordekaiser in a custom game, and halfway through I noticed that I had negative one ability-power. Has anyone else noticed this?

As a side note, I had both the new hydra and warmogs, though I don't know if these items affect anything... They did mention "spaghetti code" in the patch notes after all :P