Several potential additions for the clerical spell school:

• Bless: this could either be a low-level spell that works like it does in D&D where it gives you a to-hit and damage bonus, or it could be a high-level spell that blesses an item. Possibly it could bless items when cast at Skilled or above.
• Sanctuary: a medium-level spell that effectively makes monsters treat the 3x3 area around you like a coaligned temple for a limited time, unless you take a hostile action which ends the spell.
• Command: Drop: forces a monster to drop its weapon.
• Inflict Wounds: medium-level spell that deals damage while being in the clerical school. Damage should probably scale with skill.
• Hold Person: paralyzes a monster (or more strictly, a humanoid); fits right in since enemy priests can already cast this.
• Silence: Temporarily stops a monster from reading a scroll or casting a spell. Not specified if this should be a debuff or create a region of silence.
• Dispel Magic: Removes magical effects from a monster or multiple monsters. May be of limited use unless added to a variant where monster magic buffs are significant.
• Freedom of Movement: Grants temporary intrinsic free action, allowing you to free up a ring slot.

Implement antimagic fields as a region. They are a static, possibly invisible region inside which magical effects cannot function, including all of the following effects:

• Completely disables spellcasting both for the player and for monsters.
• Monsters behave as if cancelled, as do you if you are polymorphed.
• Enchantments do not add to AC or weapon to-hit or damage.
• Magical extrinsics are suppressed.
• Potions have no magic effects (so non-magic potions like acid work the same, but e.g. drinking a potion of object detection would consume the potion and do nothing else).
• Scrolls do nothing; they won’t disintegrate when read but won’t do anything else either. “You pronounce the formula, but nothing happens.”
• Wands do nothing; they won’t consume a charge when zapped or engraved with, and can only engrave in the dust.
• Artifacts have no special powers.

The anti-magic field trap could be repurposed into casting one of these rather than draining energy, which could be split off into a different trap type.