From CryGaia Wiki
Chain is an Ability Category. Abilities in the Chain category apply their effects to multiple targets, by first hitting the primary target, and then jumping to other nearby targets, up to a specified number of jumps and enemies.
Chain Active Abilities
- Infection - Resource consumer with cast time that sets Afflicted
- Linked Veins - Instant heal that chains to group members.
- Open Vein - Resource generator
- Electrical Storm - Resource consumer with a cast time
- Arc Flash - Resource generator
- Conditional Force
- Lightning Manifestation - Summon that uses a chain attack
Passives Modifying Chain Abilities
- Chain Misery - Weaken target of chain ability (reduce heal effectiveness)
- Chain Feed - Chain abilities are 7.5% more effective
- Vessel Walls - Self absorb barrier when using chain abilities
- Splatter - Increases targets hit by chains
- Criticality 
- Chain Reaction - Places Afflicted on targets hit by chains.
- Phantom Purge - Chain abilities have a chance to purge beneficial effect from target
- Lightning Manifestation is not a chain attack itself and will not benefit from chain improving passives
- Does not modify Chain abilities, but triggers a chain attack when making any critical hit against an Afflicted target.