Heal Team is a unique effect that can only be found on two sources. It is an effect on Harley Quinn's signature gear, .357 Revolver and its evolved version, Dual .357 Revolvers, upon using her special 2. As a character-specific effect, it only activates when equipped by her, thus, its effect cements Harley Quinn's reputation as the most popular support character of Injustice Mobile.
The second source of team heal is through Wonder Woman/Dawn of Justice's passive. She can heal her teammates by half of the amount of the Damage that she dealt from her specials and as long as they are not Blocked. This does not include Wonder Woman herself, however, whereas Harley's Revolvers do heal herself.
Previously, the Blue Lantern Ring (evolved version of Blue Ring) also had Heal Team on special 2, available to all characters. This has since been changed to heal on s2.