Highlighted weapons are free options.
Albedo is a character that can summon a Geo Construct from his Skill which deals damage on a 2 second interval whenever enemies in the field are damaged. His Burst provides 125 Elemental Mastery to the party, which is good on teams that rely on amplification reactions, such as Vaporize. It is worth noting that since his stat priority is focused on DEF (Skill scaling), you might want to skip casting Burst if your team doesn't benefit from the 125 Elemental Mastery buff.
Casting Albedo's Skill on top of a boss will summon a Silver Isotoma as long as the initial cast hits the opponent.