Insectoids of some sort would be great!

Yeah, but they will look more like this

i

Disturbing yet strangely appealing

This is a great idea. I think a champ ability that summons a swarm of tiny but easily defeated minions would go great with this faction. 

How about the Justice League , you can have acquaman, thor, Hela, also you can add characters from other super heroes from movies, like captain america, batman, 

you can also draw upon the rich mythology of each civilisation, like nordic mythology, hindu mythology, greek mythology, persian etc 

you can find new spells, like acid rain, earthwuake, chemical blast, bunch of thorns, fireblast, blind an opponent, reduce speed/accuracy of an opponent. remove magic - removes all spells cast or have a spell like anti magic which means no spell will work on all allies

wrrrr .... my idea 

i