Hm, unfortunately Spell Barrage (the teamwork benefit) affects an area, while Battle Magic Tactics affects targets. On the plus side, Spell Barrage penalises saves against "effects", not spells.
Speaking of the DMG2, the Bonding Rituals can be pretty amazing. Pick one item and you can improve it as if you had the required crafting feat (caster level = character level), ignoring all prereqs other than class features and skill ranks, but the added properties only work for you. You also get a minor side-bonus depending on the ritual. At 6th level you can take the Truebond feat, giving you a second bonus and
locate object (CL = character level, bonded item only) as a spell-like ability at will; the SLA could be used to
meet prereqs.
EDIT:
Insightful Divination anyone? Fatespinner? Unseen Seer?
Ritual Name | Benefit | Truebond |
Blood | +2 on Knowledge checks against one creature type | +4 damage against same creature type |
Dread | +2 on saves to remove negative levels | Ignore penalties of one negative level |
Faith | +1 Will versus spells/SLAs of outsiders of alignments different to yours | Attacks and magical effects coming from the item gain your alignment, and abilities that improve your alignment-based spells apply to the item |
Fire | +1 on saves vs fire effects | Fire resistance 10 |
Honor | +1 initiative while the item is on your person but unequipped | +4 dodge to AC vs AoOs from creatures you haven't attacked |
Magic | +1 on caster level checks while the item is equipped | +1 on saves against spells/SLAs while the item is equipped |
Purity | +1 on Con checks and Con-based skill checks | Fatigue does not inflict Str or Dex penalties |
Song | +1 Perform while item is equipped | +1 caster level for spells with both V+S components while item is equipped |
Theft | +1 Open Lock/Search when taking 10 | +2 Open Lock/Search when taking 20, +2 Bluff/Disable Device/Sleight of Hand when taking 10 |
Travel | +1 Survival and any check boosted by the Endurance feat | Nonmagical terrain never halves your speed |
I've left out the prereqs and the tasks you have to perform to create a bond.
EDIT: Combine Heighten Spell-like Ability
CArc with
Godsight or
Raumathor Heritor and you can bypass the prereqs for the Loredelver
RoD PrC.