The Bloodline Battle in action.
The Bloodline Battle is a mini-game of sorts that was featured in Power Instinct Matrimelee. It is activated when both players use their taunting moves at the same time, or anytime during the one-another's taunting animation. The fighters then dash over to each other as a monitor drops in which will randomly display a particular button that has to be pressed (A, B, C, or D). If successful (such as if one fails to press the button on time, or presses the wrong button), damage will be dealt.
This mini-game will continue for five rounds before ending, and if the fighter is successful in pressing the last button on the fifth round, it will knock down the fighter. On the other hand, if both fighters end up with a draw on each of the five rounds, there will be a second set of rounds to determine a victor, and the pace will be much faster. This set of rounds can end with one button if the timing and execution is right. If there are 11 more draws, then the battle will end and the match will resume.