If you are familiar with Naruto, some of the Ninja have Techniques were they enter a "Mode'
Some of them symbols or patterns appear on their head and around their eyes as an effect of them unlocking hidden power, and may allow them to use new much more powerful; techniques.
Similar to a Shikai or a Bankai, or even the Kaioken.

For Laskey, dark Circles Form around his eyes and a Cross appears on his head when he enters his "Battle Priest Mode"
He becomes Sharper, more Focused, Faster, and his Spiritual Energy Increases 12Fold, unlocking and allowing for much more Powerful Techniques his body wouldn't be able to perform or Sustain.

Art is by  monstrovod
Also Known as blackwitebeast on DA