Humongofrog needs a base damage increase. It should be at least a little stronger than meteor. Yes, I know fire is stronger then myth but still. Fire also gets: Fire dragon and Rain of fire. Those are both very strong AOE spells. Myth doesn't get anything like that until they complete Castle Darkmoor. I mean I can still kill enemies with frogs, but it takes forever. Especially when you get up into Azteca, then its basically useless. Honestly, you are better off just using Medusa on each enemy.
I think meteor is stronger more because of the story than because of PvP. if it made sense for the story or something it would happen but as of now most of the below tier 5 spells favor story relevance over PvP. I think myth needs a small buff just to give it an edge but i don't think that's how they're going to do it. (if they do)