Wyndstryker
Member
Mercy probably needs double damage on her pistol to become a viable healer. The main 3 healers all provide good DPS/offensive potential on top of their healing. It's a no brainer to pick them ahead of Mercy who essentially renders you 5v6 against a good team.
Just overhaul her a bit. Her beam is both Heal + Damage boost but reduce the boost a bit.
Then give her an AOE repel around her to push people away.
Non-damage potentially offensive move that also improves survivability and a useful change to her healing.