Illari

High healing output from Pylon and Solar Rifle (Heal)

Pylon prioritizes healing the ally in the most critical health, so healing gaps for allies rarely occur. Also, Solar Rifle (Heal) has a very high healing output of 115 heal per second. Although there is a charge limit, it temporarily provides higher healing output than Ana or Kiriko.

Disengage via Outburst

Even if a flanker or tank closes in on Illari, she can create distance with Outburst. By holding Outburst, she can jump higher, so it can also be used to take high-ground positions.

Hitscan primary fire

Because her primary fire is hitscan, she can easily apply pressure to aerial enemies. Illari has healing output from Pylon, so even when she commits to attacking she is unlikely to run short on healing, making it easier than other Support heroes to create chances to target opponents.

Destroy Pylon first

Illari generally tends to place her turret at an off-angle position relative to where opponents usually enter, so being mindful of entering from the side makes it easier to destroy.

Fight with heroes that can kill in one shot.

Because Illari's allies are constantly healed by Pylon, she is very strong in poke-style fights where damage is traded from a distance. Using heroes like Widowmaker or Hanzo that can finish off enemies in one shot makes it easier to negate Pylon.

Fight with a dive composition.

Illari's Pylon has a long cooldown, so with a dive composition, destroying Pylon and immediately diving works well; since Illari does not have very high disengage ability, it is easy to gain an advantage.

Pylon heals allies for 50 per second, but its healing on Illari herself is halved to 25 per second, so avoiding placing Pylon solely for her own sake gives overwhelmingly better healing efficiency.