Repair - Recovers HP for the target (Construct) ally. Pure Constructs cannot be healed and heal potions don't work on them. They must be repaired. Repair works on Construct and Living Stone allies as well.
Pure Constructscannot be healed in the conventional way, but must be repaired. This affects all Constructs with the trait Construct.
Repair is the only way to restore the Current Health of Constructs, because neither Healing Potions, Lifesteal nor Healing Runes, nor Heal itself works on Constructs. Normal Regeneration is also ineffective. But there are exceptional Constructs. These are the so-called Living Stones, which have a Trait with the same name. These stone heroes can be both repaired and healed.
Another important point is that any ability that has a healing component will not work with pure constructs. For this reason, Zen, for example, cannot use Enlightenment to accelerate Constructs.
Constructs can also be infested by Doom. This is the only known Debuff that makes a repair impossible.
Bauble is probably the best mechanic here, as he can repair a single construct ally with his Basic Attack or repair and heal all allies at once with his Positive Charge.
The Furnace has the ability to give all Constructs, pure and Living Stones, a self repair trait. The repair effect works passively and increases with the number of Constructs in the team.
IFF Targeting (Basic Attack): Melee physical attack on target enemy, OR heals target friendly construct, OR target ally gains a class-specific buff (Tanks get DEF+, Healers get CRIT+ and SKL+, Casters get +1 ENERGY, all others get ATK+.) Positive Charge (Special Attack): Heals or repairs and adds electric skin to all allies.