How to pass Ziraks x2 without losses?

[kbnewbie]

Hi there,

I'm playing on hard difficulty with Mage and it seems like I've completed most of the game. There are supposedly three bosses left, but now I'm stuck with Ziraks because I've no idea how to kill him without casualties. Also, there's a wretch on Verona (who's killable but it'll be very difficult) and a mage in a tower (100000hp, damn it).

My save file can be downloaded here.

So, please, take a look on my save and give me some recomendations on how to finish this game without casualties. I wonder if it's possible at all

PS I managed to eliminate the first part of Ziraks but ... just look at the screenshot: