Non-meta builds often are overlooked when it comes to balance. The general consensus is that if it was overpowered, it would be in the meta. But just because it’s not in the meta, doesn’t mean a build can’t be broken. There are at least a few broken builds in non meta: Overtuned for burst combos or near-immortal bunkers.
Bunker Rev is in my strong opinion overtuned for sustain. I don’t think Revs overall are overpowered, but this particular build is broken.
Condi thief is overtuned and broken.
And I strongly believe the burst combo from power shatter GS chronos are way overtuned. And what makes it worst is that the burst combos is often done from stealth and preemptive blocks won’t save you, but the opening daze is unblockable. It interrupts blocks to stun you while blocking, and then GS#2 bounces to you and back to you is also unblockable. And all of the damage hits in about 1/4th of a second, through blocks and while you are stunned.
This burst combination is broken. Whether or not, GS mesmers are in meta or not, these type of burst combos is unhealthy for the game. It takes no skill because anyone can memorize a burst combos and use from the safety of stealth, or use a macro which is often the case.
Here is a pic of me getting blown up, while i was blocking, from stealth, in 1/4th of a second. My amulet also has 560 toughness, but I might as well had 0 toughness against this overwhelming burst combo.