[Agema]

Baalz probably meant mid to late game.

Bear in mind once Atlantis gets underwater and builds/finds a castle, you can recruit national W2S1 +100%EFSW mages. The W2S2 ones can cast antimagic, so you shouldn't need your pretender for that spell at all.

You want to try to build most of your castles on land as you get better unit recruitment choices from them, and much more cost efficient research mages. However, you should get (build if you can't find) at least one underwater castle quickly as it will be vital to expanding your magic paths.