Mirage had to do this and risk his all. After all, he doesn't have any choice anymore. His situation compels him and it's already too late for him to retreat by giving up.
It had started to become a kill or be killed situation when he continued to attack the Black Tiger despite his shield breaking under the fierce assault of the beast.
The hairs all over his body were rising on their ends as the scent of death's ominous smell becomes stronger and stronger as time passed by.
It felt as if the Grim Reaper itself was about to come to him and claim his life. He was overcome with the feeling of dread as he came to the realization that he really had no way out of his situation anymore.
Mirage knew that he couldn't falter at such a crucial time thus he took multiple deep breaths to force himself to calm down.
The negative emotions enveloping him were then washed away and he barely managed to resist the strong urge to give up earlier.