OmnicMeta recently released its report on the most popular PC mains for Season 4 of Overwatch's Competitive Play. Among the lower tiers, Mercy mains constitute about 20% of the competitors, and the difference between an average Mercy and a good one really rests on three simple tweaks to your gameplay.
I'm by no means a Grandmaster Mercy (I'm sitting solidly within Gold), but given the number of game's I've lost due to a ground bound Mercy idly following a Reinhardt, it seems prudent to lay out a couple of simple tips to help your (at least Silver and Gold) teammates say "Great Heals, Mercy!"
Tip One: Use your Ultimate as a personal shield
Mercy's ultimate ability, an area-of-effect (AOE) resurrect, has always been a game-changer. After a recent patch this resurrect got an amazing buff: It now gives you a few seconds of damage invulnerability. Watch the video below:
The video starts off with me healing a Reinhardt from the safety of the center tower; I'm just barely keeping him in range of my staff while remaining mostly hidden, but as he charges in, I have to adjust. Seeing a nearby Pharah who needs a quick top-off, I guardian angel in, heal her, and then put myself back on the Reinhardt who uses his Ultimate, Hammer Down, and slaughters most of the enemy team with my damage boost.
The enemy Pharah, looking to even the playing field again, uses her Rocket Barrage and kills a teammate while simultaneously dropping me to a perilously low 22 hit points. Seeing an ability to get my teammate backup, I use my resurrect and fly through the enemy barrage without taking anymore damage.
Tip Two: Float after, but don't (only) heal, Pharah
Don't get me wrong, there will be times you need to pocket heal a Pharah, but even if you're the only healer on the team, and your focus is on keeping your Reinheardt alive, stay in the air as long as possible.
In this video, I start off by healing and buffing our Pharah, but quickly adjust to resurrecting our team. Once they're back up, I fly behind my team's Pharah, and float back down to the ground while healing the teammates who are fighting a losing battle on the point.
Tip Three: Don't be afraid to use your gun!
Rarely should you be trying to use Mercy as an offensive hero, but occasionally you're going to find yourself isolated, or in a situation where just "a little more" damage is needed to kill that Mercy/Bastion combo or clear an objective. One such example is below:
My team is straggling into the point one-by-one in that all-too-familiar "Touch the Point!" rush during Overtime, and it ultimately comes down to me and a Mei trying to clear the objective. Traditional logic would say: Keep the Mei alive, and hope for the best. I opt for a more dramatic route: Gun them down!