Female teeneger that rides on bubble, main attack is little projectile bubble shots that have low range, secondary attack is shotgun like shot that have even lower range but have knockback effect
1 - creating bubble around certain area that slow enemys that lasts 5-10sec - 40 mana
2 - creating bubble of poison that makes enemys take dmg for 5 sec ( the effect refreshes itself every 1 sec while enemy is still in bubble ) that lasts 5-8sec - 50 mana
3 - creating bubble of thunderstorm that makes enemyes take dmg while being in it, there's 10-40% chance to stun enemy - 80 mana
It all goes around add-ons, not upgrading and not building more. Every effect can be stacked up to 4 times so their effects/dps can be increased.
1 - base bubble ( you can even call it aura if you want ) it doesn't do anything by itself - 30 gems
2 - adding slow effect to base bubble - 30/40/50/60 gems
3 - adding poison effect to base bubble ( the way that deal dmg is same as ability but it scales with defense power ), poison attack rate is increased but only in bubble and poison effect doesn't last longer even if you upgrade add-on - 50/60/70/80 gems
4 - adding fire effect to base bubble ( way of working is same as poison except in this add-on enemys are ignited, not poisoned ) - 60/70/80/90 gems
5 - adding thunder effect to base bubble ( same as ability ), chance of stun is increased with every add-on 30%/40%/50%/60% - 80/90/100/110 gems
The way it works is that you can place every single add-on on base bubble and upgrade every single one of them to max so it will deal bigger dmg while doing it in different ways. Add-ons can't be placed by themselves.
I hope you liked my idea.