Merchandise!

David's devotion to his cause has grown so greatly that he can now shrug off hardships that no mortal man could, this also started a process of healing his birth deformities as the good inside his body began to heal his outward appearance, although this process would take time.

because of the radioactive ooze spilled on his arms, he has become more durable.

Orion’s Vigor is a passive ability that channels the relentless energy of the celestial hunter. With this power constantly active, the user’s body becomes resilient to all forms of physical stress, allowing them to push through pain, exhaustion, and damage without faltering. Whether enduring brutal blows or relentless fatigue, they continue forward, fueled by an unwavering, cosmic determination—just as Orion tirelessly roams the night sky, never slowing, never yielding.

Much like the name suggests, a rush of adrenaline courses through Kaji's body - allowing him to ignore his injuries and other penalities for the duration of combat, and fight at his fullest potential.
You could also maybe call it him just 'going into the zone', more or less.

Ichabod's body has gone cold, and so he looses most of his bodily feeling. Crossing over more and more.

The mobster's been through tougher scrapes than this. A few cuts and bruises won't stop them.