Mimetic

This special ability can only be placed on melee weapons. Each time the wielder damages a creature using a mimetic weapon, he gains resistance 10 to one energy type that the creature is resistant or immune to for 1 round (if the creature damaged has multiple types of resistance, the wielder chooses one of those resistances to take). This resistance stacks with itself, to a maximum of 30 points of resistance against a given energy type, but not with other sources of energy resistance. The creature's own resistances and immunities are unaffected.