no loss mage, Im stuck!

[clinek]

ok, ive beaten KB:AP with no losses as a mage and ive beaten KB:TL with minimal losses. There is one spot where i just cant figure out how to get by without any losses. The dwarven castle with demons is the only thing blocking my way. Normally, i would travel through the demon portal and get access to all the good items, all the good units, and all the good spells but lucky me, there is that one hero and another stack of units right in front of the gate. There is no way to beat either of them with no losses (ive tried) so the demon area is off limits at the moment. I have found very little useful units, (i found inquisiters but there are only 38 of them to hire which is useless) Nobody sold ice snake, gift, or any spell that would be useful. my units consist of Archmages (i dont really like them but they are actually much more useful than anything else) cannoneers, evil beholders, giants, and cyclopses. I i used higher level units so that i could implement "fear" to more enemy units. The castle doesn't have any archdemons, but it does have red dragons which are a pain in the ass to kill when you dont have ice snake. If anyone has a suggestion on what i should do, maybe a trick that im not aware of to get ahold of some more level 5 units, or anything that would help to get past this danm castle i would be great

Thanks