sharp fog
Assist Breaker is a unique form of "Burst", available in a few fighting games now, that allows a player to break out of a combo, at the cost of a massive resource spend/cooldown that prevents using it frequently. Generally, when baited, it will be horrifically minus on block (at least, when using Guilty Gear as the standard, this is true), and so it's both a massive resource spend and a major risk in some parts of a combo
The differences in InvincibleVS are that one of your assists must be alive, and take a life percentage as temporary damage (which can be regenerated passively while out of play), and 2 out of maximum 3 boost gauge from the point character. It is also not minus on block, in fact it is usually very plus and can only situationally be punished that way, a seemingly very rare circumstance, In addition to being extremely plus on hit, allowing the point character in either situation take back control and potentially get back their boost, recoverable health, and even tag out at the next opportunity to the uninvolved character to quickly regenerate both the boosts and life, in addition to playing a character that has breaker available again
What is not explained, is how to effectively counterplay this. It's not necessarily something that needs to be tweaked, but I have yet to find any real way to call it out besides popping a super (which seems inconsistent in both function and reward, I've labbing this as Bulletproof and I not only need a really specific super timing that I can't always cancel on, but I can't combo afterwards even with an Active Tag (Tested as Bulletproof/Lucan Vs Invincible/Omni-Man)), and unrealistic combo extensions such as crumple>block breaker> dash up and keep up the combo.
The result is that the first player to land an attack effectively eats a guaranteed breaker (as they cannot super in response at 0 bar), and will have little in the way of effectively capitalising on this spend.
You can try snapback to capitalise on the health lost, but by the time you get the next hit you still won't be able to kill, and so you've won 3 separate interactions upon hitting the snapped character, and still everybody is alive and you need another RPS situation.
I think ultimately given context, is that my suggestion is we either need an explanation of some other method i haven't considered to actually punish players for breaking and stalling every time they take a hit, or we need a tweak that makes it a greater risk or spend. I think right now it's the most problematic mechanic by a margin lol 
frosty cypress
wary frigate