Thunder Hammer is a technique officially adopted by the Charlemagne Kingdom army, and its purpose is to kill.
Therefore, the power of Thunder Hammer is fatal enough in one blow. Even though the young man was fearful of losing his life, he deliberately reduced its power. At the very least, Roland, who was on the receiving end of the strike, should've been suffering from convulsions in his limbs, burnt skin, and lived a life of partial paralysis for a while.
But Roland got up from the ground.
This certainly wasn't a miraculous result of the Mother Goddess making her appearance, but rather, it happened because Roland still had a breakdown formula attached to his fist. The moment he sensed the abnormality in the Mana overhead, he quickly converted the breakdown used for destroying the Circuit Worm into a deterrent against the Lightning Strike Technique, thereby reducing the damage.
Despite this, Roland was not unscathed.