You will want some ranged spells to balnace your melee stance. Fireball is the obvious, at least in the early levels. It has the added advantage of doing some damage behind walls.
You want things that even the odds vs mobs, and reduce the foes you have to face simultaneously. Web, Blood Skeletons if you can find it, regular skeletons if you can't. Maybe Charm.
Bee Swarm if you are using that 'official' mod.
I think Heal All to have a guaranteed 100% recovery (if you are patient) before proceeding after hurting battles.
You'll be going in close deliberately, so Elemental Protection is probably more important than Elemental Overload.
...these other transforms carry some significant extra HP when the pet is transformed....dreamrider