I doubt this idea is worth an entire new weaponskill or job, but I could see it work as a gimmicky H2H weapon like Vampiric Claws or Birdbanes.

Armguard (R)(E)
(Hand-to-hand)All Races
DMG:+30 Delay:+84
"Shieldguard"
Lv.99 WAR / MNK / RDM / DRK / PUP

Shieldguard : allows hits to be shielded using Guard skill, but disables guarding.

Or perhaps as a subslot item for H2H weapons:
Armguard
(Grip) All Races
Chance to block incoming hits +5%
Lv. 99 MNK/PUP