Though Bastion appears to be gentle and even harmless, his core combat programming takes over when the unit senses danger, utilizing its entire arsenal to eliminate anything it perceives as a threat. With Bastion and its gentle nurturing senses towards its pet bird, Ganymede, its easily mistaken as a peaceful unit.
Bastion may be difficult at times, but this cute little robot is no where near “overpowered” or “game-breaking”. All it takes is some coordination and strategizing to take down a skilled Bastion.
Tracer: With Tracer’s highly mobile nature and fast charging ultimate, Pulse Bomb, she is an excellent counter against Bastion. Since Bastion is always in sentry mode its an easy stick target. Tracers, do yourself and everyone a favor and don’t just blink up to bastion try go around and behind him.
Genji: By coordinating with your teammates, Genji can poke down a Bastion from afar, then as soon as you see Bastion turn to you, throw up your Deflect. This may require a bit of mind-games as you try to outsmart each other, but with a sieging team the Bastion will either be deflecting Genji’s damage or holding back from attacking.
Pharah: Pharah’s rocket launcher is a good counter for Bastion, just be sure to be at a safe distance and land yourself a free kill. Use Pharah when Bastion is in really bad positioning.
Snipers (Widowmaker & Hanzo): Use snipers to eliminate a poorly positioned Bastion from a safe distance.
Get around him: Bastion has 360 degrees of vision in turret mode, but its still hard for him to catch enemies that flank him. Use heroes like Tracer and Reaper to sneak behind Bastion and deal lethal damage. Lots of Bastions will sit in the middle of the field, being cocky and thinking that they’re playing the “OP” hero. Take advantage of this bad positioning for free kills.
Don’t walk into his line of sight: As newer players are still learning the game, they tend to walk directly in front of Bastion only to be annihilated by his barrage of bullets. Unless you’re Genji, stay out of sight. If you can see it, it can see you.