The Lore of Metal is a pretty strong lore that focuses on a variety of damage spells and some decent augments and debuffs.
The passive is actually one of the better ones, +10% weapon damage map wide is quite good. Final Transmutation is essentially a Fate of Bjuna and equally effective. Gehenna's Golden Hounds is an efficient vortex spell that moves randomly, but does high damage. Glittering Robe is a decent defensive spell, but if your opponent has large amounts of armour piercing damage, it is a bit wasted. Plague of Rust is good if you run into an enemy with way too much armour for your units and can help level the playing field. Searing Doom is a good bombardment spell for blobs of enemies. Transmutation of Lead actually destroys an enemies damage output for its duration. Very little damage will go through to your units.
Some of the above info is a bit misleading, final transmutation is the strongest and most expensive direct damage spell. its acts like spirit leach hitting one model in each unit at time doing on average about 2100 damage total across multiple hits if overcasted. every unit or single entity is hit with a more than double strength sprit leach effectively, all are effected separately. if you hit a few valuable targets its damage and efficiency can be much higher than spirit leach even if you only hit 3 or more models. spirit leach does about 116 points of damage per WOM spent, overcast final transmutation does 75 damage per winds of magic per unit affected. so its actually better vs single targets/ elite units even if you only hit two, 3 or more targets and its greatly overtakes it in terms of damage done per winds of magic spent. only flensing ruin is nearly as effective overall. Still it is extremely expensive with a longer cooldown.