You are a deity creating heroes, and they have this super mode

So they don’t get azula’d

when they reach half health they shout “WEAK” and the super mode activates

I have AO characters that I plan to make a comic on (and maybe eventually share in the forum).

However, their “super mode” will probably just be them on adrenaline and pushing their bodies past their limit, nothing big.

Though, as I worked on another character, I came to the result of a Berserker attempting to master 3 fighting styles, Thermo/Sailor/Iron leg. He can use the styles sparingly, and if he overuses them (which in this case, would be him going supermode), it takes a HEAVY toll on his body.
Overusing Thermo’s super mode gives him much faster speed and agility, at the cost of overheating, cardiovascular issues due to the increased heart rate, heat strokes and even burns on his body.
Overusing Sailor’s super mode makes his attacks hit with much more strength and impact AOE, at the cost of bringing him heavy exhaustion, dehydration, worse case scenario a coma, and WORST case scenario, organ failure and death.
Overusing Iron Leg’s super mode gives him black iron coating, increasing defense and knockback resistance, at the cost of anemia, muscle fatigue and difficulty in breathing, lastly making him even weaker and vulnerable than “base form”.

These are meant to be used as a last resort, as trying to use these constantly in a fight would be even counterproductive. He has to keep a balance in the styles he’s using, or he may actually die while fighting.