Arcane
From MHWiki
The Arcane (used in reference to weapons) or Forgotten (used in reference to mice) power type is thus far exclusive to the Catacombs.
Description
Traps utilizing arcane damage come from sources shrouded in mystery. The strength of arcane damage increases proportionally against forgotten mice, making the traps especially effective in the Catacombs.
Types of Arcane weapons
Currently, there are two Arcane weapons available in the game: the Obelisk of Slumber and the Obelisk of Incineration.
Effectiveness
Arcane weapons are very effective against Forgotten Mice, namely:
Arcane weapons can also catch Physical, Shadow, and Tactical mice without any bonus or penalty.