I am finding we don't have a list of Support characters and a description of their abilities/skills... i'll add info to this as i get around to it.
Rene: Dig (ability), Treasure Hunt (skill)
Dig makes Rene search her current position for an item. There are no random items in this game; every map variation and unique battle has a fixed set of dig spots and treasures. The Treasure Hunt skill is basically a radar that will make dig spots light up when Rene is in range, but the "radar" effect only updates while Rene is on Stand by-- the radar does not update until she has completed her turn and has gone back to Stand by.
The Treasure Hunt skill's range increases based on level.
Gary: Backup (ability and skill)
ATK Up and Accuracy Up. His Backup skill can be leveled up to increase the range he can "cast" the effect. The "spell" itself is the same shape of a low-tier Force Bead, 0-1 radius, and only affects allies.
Ema: Pack (ability)
Ema's special ability gives her access use any item in your inventory. She can still equip and use personal items like normal characters, but the Pack ability is unlimited.
Carrie: First Aid (ability and skill)
Carrie heals all allies around her in a 1-2 unit radius.
Yu: Heal (ability and skill)
Yu has a single-ally heal with a range of __ units and also remove negative statuses.
Noah: Steal (ability and skill)
Cedric: ___ (ability), True Godspeed (skill)
Cedric's active support ability gives an evasion rate boost to allies within a 0-1 range. However, he also has a tremendous MOV stat thanks to his True Godspeed skill, which gives him a unique ability to cover tons of ground.