When the fight starts, the Gil Snapper will be buffed up by the surrounding Sanctum Monks by elemental resistances. The only elements not Bar-resisted are Light and Lightning, so those are the recommended attacks to use, or Drain/Drain Force. The Gil Snapper will protect itself with a 10-hit shield when it gets its turn, and will get further buffs by the Monks that acts as supports.
After the first Gil Snapper is defeated, a second Gil Snapper will spawn in front of the tree with the bones, as well as 2 melee Sanctum Monks. 2 more melee Sanctum Monks will spawn after the second Gil Snapper is defeated.
Brutal Difficulty #1 and #2 enemy placements are the same. The main difference is just their levels.
Map (Brutal #1 and #2 have same map)
6 Sanctum Monks surrounding the Gil Snapper (Brutal #1) and will always start their turn by giving Bar elemental resistances to the team.
After the first Gil Snapper is defeated, a second Gil Snapper will spawn near the tree with the bones, as well as 2 melee Sanctum Monks near the corners of the map.
2 additional melee Sanctum Monks spawn location after the second Gil Snapper is defeated.
Brutal #1 Enemy Stats
Gil Snapper Stats
The second Gil Snapper that spawns after the first one is defeated has the same stats, but half the HP.
Sanctum Monk Stats
All Sanctum Monks mages have the same stats.
2 melee Sanctum Monks (1 light and 1 earth) will spawn after the first Gil Snapper is defeated. 2 more will spawn after the second Gil Snapper is defeated.