Young Stuart had used the possibility of fusion for the first time for a few reasons.
He wanted to prevent those individuals from sacrificing themselves in this place. That, of course, was due to the damage that such opponents could do to the structure of this city, the secret base of the Black Plain Army, and the viewers in the vicinity.
After all, of the three individuals, two of them were at level 55, while the last one was at level 56. Consequently, the explosion generated by the sacrifice of these three could be many times worse than what had happened after the sacrifice of that level 54 assassin that Minos had previously faced.
But as that desperate attempt by the former assassin of the Scourge of the Devil had created a crater with a radius of hundreds of meters, then something many times worse could have occurred here!