Overwatch – Freezing with Multiple Mei’s

What makes Mei threatening is her one-two combo. Once she locks you down with her primary fire, she can use her alternate to finish you off. However, her primary fire requires some time to immobilize and she can only target one enemy at a time. This leaves her weak to grouped assaults, burst damage, and hit-and-run attacks.

Ignoring coordinated assaults as they might be difficult for pub groups to pull off, Mei's short range leaves her weak to mid-range and long-range heroes such as S:76, Widowmaker, Hanzo, and Pharah. Provided they keep out of range, that is.

Heroes with high burst damage like Roadhog's hook+scrap+melee combo or McCree's alternate fire can also deal with Mei though this is a riskier proposition as they have to get in close range and not landing their burst leaves them open to be frozen and icicle'd.

Somewhat counterintuitively, heroes with high mobility such as Tracer and Genji also have an advantage against Mei, though this is very dependent on tactics. While Mei can lock down these squishy speedsters, she needs 2 seconds of consistent damage to do so. Therefore, she excels at prolonged encounters and Tracer/Genji need to realize this.

Don't expect to kill Mei in the first encounter. She has 250 health and most likely her Ice Block. Instead, whittle her down with guerilla tactics, making sure to use your high mobility to dip out of combat every now and then to avoid her freeze. If you have your ultimate, bait out Mei's Ice Block. While she can exit her Ice Block at any time, most Mei players will choose to spend the full duration to recover as much health as possible. Either count the duration (4s) or listen for the audio cue and use your ultimate right as she comes out of Ice Block. Tracer's ultimate will one-shot her and Genji needs 3 strikes (although in practice, it's usually 2), which he should be able to accomplish in 2s.

No. Shields absorb enemy projectiles from both sides. Likewise, allies can fire through it from both sides. That is, the team the shield belongs to determines whether projectiles pass through it.

My only source is primary: approximately 150 hours of play, much of it as Reinhardt.