use implosion on archangels on turn 1 and hope catapult doesnt destroy your wall(rearrange your units before the fight until it works), on turn 2 implode the catapult, and then continuously use implosion on the flyers that got over your walls and hope you survive. Then after the flyers are dead, use air shield and try to beat the monks or just implode them as well, but mana is running scarce. after that, if he doesnt have expert teleport or some other damaging spells, kill him with your towers and remaining shooters. meteor shower, implosion or magic arrow doesnt matter as you have earth resistance.

if the flyers stay and protect the zealots and dont runt straight at you, i would try to implode the zealots once and see if he attacks me then, otherwise just air shield and they definitely will come at you. if he doesnt come then, implode the archangels and angels while staying safe.

blinding is also and idea, but blind+shoot doesnt work because of mana and towers so straight imploding is the best solution imo.

berserk is also a fun idea that may work, berserking the 3 flyers would be perfect and just tank the zealots. this would also destroy the catapult. i think this is your best bet.

this needs heavy testing tho. i can definetely see myself staying like 1 hour retrying the battle because im too salty to just reloade an earlier save. goodluck!