This battle starts when M-24 stands up against Jake to protect the children.
Prologue
Jake and Mari kidnap the children to wipe out all existing witnesses. But M-21 prevents the assassins from killing the children by proposing to lure out the 'other kid' using them. Although not permitted to kill, Jake decides to entertain himself with fighting Shinwoo until the 'other kid' shows up. At one point, Shinwoo tries to stop Jake from attacking his friends and clings to his leg with all his might. M-24 cannot stand watching Jake hurting the children and makes a move to let the children escape.
Battle Summary
M-24 punches Jake into a wall and tells the children to escape quickly. He carries Shinwoo over his shoulder and runs with the children. Jake gets up and chases down the children and M-24, breaking through doors and walls in the process. Hearing Jake's rampage, M-24 stops on his tracks. He urges the children to follow the way to the elevator and tells them to escape while he tries to hold back Jake.
Jake jumps at M-24 and lands while dodging his punch. He easily grabs M-24's head and smashes him headfirst to the ground. Jake continues landing attacks on M-24 while avoiding getting attacked himself. Jake comments on M-24's strength and asks him if he was hiding his real strength from the Union. M-24 does not respond and attacks again. M-24 pounds both his hands to the ground which shatters the floor but Jake jumps to the side and attacks from behind. He hits M-24 with his knee and pushes him to a wall. M-24 tries to punch Jake but Jake easily avoids the attack again. Jake transforms his hand into claws and lands a finishing blow to M-24's chest.
With the assumption that M-24 is finished for good, Jake proceeds to follow the way to the elevator where the children were headed and tries to further harass them. But Jake is suddenly grabbed from behind by M-24. M-24 hits Jake head on in the wall and then further smacks him into the ground but to no avail as Jake pierces his heart. Ignoring all pain, M-24 hits Jake into the wall with his full strength, thus destroying the wall completely.
Aftermath
Jake emerges from the wreckage without any apparent damage and is about to kill the children when Raizel and M-21 arrive. M-24 is inside the debris; his body gradually disintegrating and he himself just holding on until he exchanges his final words with M-21 after Raizel annihilates Jake.