Infernal Dragon is very overtuned

So, each of the dragons is suppose to be filling a different role. This makes sense. Except for the infernal dragon. It is grossly overpowered.

Because it is giving attack damage and ability power, it is increasing ALL your damage vs EVERYTHING. That is a huge problem. It means that every infernal dragon you take boosts your minion pushing, tower pushing, jungle clearing, and champion pushing (its intended buff area).

Infernal dragon should be buffing damage to champions so that it actually is increasing champion fighting potential and not just straight buffs.