in general kill the mage or cleric first... any spell they manage to get off will hurt you
as a pure tank Shadowheart is nice, in giff armour and shield she starts at 19 and there is a better shield later to reach 20 [unbuffed]... watch some some youtube vids to see best ways to use her
imo the key point to this battle is hold off a bit until you are level 2 or 3... i always do it at level 3 but its very doable at 2
