Yes, check the link in my last post. He turns into one of those.
You can make new spells for the transformed form. Set some spells up as 'normal' spells instead of hero, and give them to the alternate form unit, he'll have them when you switch. If you want levels for the alternate form's spells, then use my trigger but duplicate it to work for the alternate form also. The bear form spell works this way, you can stay shifted until you decide to shift back. And you can make the shapeshift the ultimate spell, just set it so it can't be learned until level 6 or whatever. As for custom spells, my druid has custom spells too, those 2 spells in those triggers I posted are both trigger enhanced spells. All works pretty smooth