User blog comment:Emptylord/Class Reworks - Itemization Follow-up/@comment-28280538-20160512201236/@comment-1330314-20160515100349

I don't think the above Abyssal risks creating an arms race, since it has enough conditions (short range, application over time) that a) not every AP champion would want to pick it, as you yourself pointed out, and b) enemies can significantly mitigate a large part of the item's effects by keeping their distance or only trading in short bursts. Abyssal was also never an option for long-range mages in the first place, and when the above version was added onto the PBE, it was intended mainly for AP fighters. Burst champions, on the other hand, have, which works better on hard AP-scaling champions and offers better magic penetration instantly.