Maybe so XD. His second main goal/dream IS to become the world's strongest illusionist, although I think early on I'll have him focus more on tricks and non-illusion-y combat and only use illusions to be extra-tricky or give his attacks an extra punch. So combining with the other two into an ultra-broken attack like that seems pretty cool. 

Although can't Box Weapons only use certain kinds of flames so wouldn't giving Cyril's Storm Box Weapon with Cloud Flames seems less likely...

Also um, I hope people like Prospero and I'll try to play him well.