Force Missile Mage: Overpowering Missile vs Reflective Shield?

Question

A slightly oddball question. Let's say I have two Sorc 10/ Force Missile Mage 5. Let's just say.

They both have Overpowering Missile:

Overpowering Missile: At third level, the force missile mage's magic missile spells become especially potent, breaking through spell resistance more readily than normal. She gains a +2 bonus on caster level checks to overcome a creature's sell resistance with the spell magic missile. This benefit only applies to magic missile spells she casts. In addition, a force missile mage's magic missiles penetrate shield spells and brooches of shielding as if they didn't offer protection from the spell.

and, they both have Reflective Shield:

Reflective Shield (Sp): At fourth level, a force missile mage becomes immune to the spell magic missile. For the purposes of being affected by magic missile, a force missile mage is constantly treated as under the effect of spell turning, thus reflecting offensive magic missiles back at their caster. If that caster is protected by the shield spell or a brooch of shielding these reflected missiles are negated. Missiles reflected against a caster who also has a spell turning in effect require the force missile mage to roll on the spell turning mishap chart (PHB 283).

So, given that they are throwing Magic Missiles at each other (they're not all that bright), how would they interact? Would they function as normal, would both players have to roll on the spell turning mishap chart, or would they just cancel everything out?

Answer 1

The answer depends on whether or not either or both of them has shield (or similar) active.

Case 1: Neither has shield active

With no shield spells in play, Overpowering Missile does not come into play at all. Reflective Shield does not replicate the effects of the shield spell, and only refers to that spell when it is active on the other guy.

Instead, the situation is identical to if both of them had an infinite version of spell turning active: a resonating field is created, and you have to roll on the chart.

Case 2: One has shield active

The one with shield active has his own missiles, turned by his opponent’s Reflective Shield, negated by his shield spell. The missiles turned by Reflective Shield are explicitly negated by shield or similar, which trumps the caster’s own Overpowering Missile feature (specific trumps general: his magic missiles generally ignore shield, but Reflective Shield specifically says the turned missiles don’t ignore shield).

The one without shield overcomes his opponent’s shield due to Overpowering Missile, but then the magic missile is turned by Reflective Shield. He has his own Reflective Shield, so you get the same resonating field as you did in Case 1, but only on his turn rather than for both their turns.

Case 3: Both have shield active

The shield on each of them negates their own turned magic missiles, and so a resonating field never occurs. They are literally burning spell slots to no effect.