Cool the AoE freez O.o

Hey ! To start, i've a bad english (i'm french ^^'), so excuse me if you don't understand :3

I've a big problem, I've 2 blades and a knight, and i play with this 3 characters at the same time, cause i've a good pc. But my problem is here : When i aoe, with ONLY THE KNIGHT'S ACCOUNT, i freez, and i must restart Drakonic to play, it's when i hit mamoth, and cannibals mamoth ... i never had this problem, so i need your help, it's the server, or me who have a problem ?

If you want to try, go to azria, take 20 mamoths, and aoe them, i freez with this, but not 20 yettis ... please try, and say me !

Thanks !