Gale's Qi was lost in the whirlwind of energy, as his attempt to help bring stability to Xiaolin's channels failed before he could even start.
This was supposed to be impossible, but Gale had seemed impossible happening more than a handful of times. He pushed harder, coming with more of his Qi to stabilise her condition.
He couldn't just watch her groan in excruciating agony, as he Protected her with all his might, using his second fate lock. Even with that, he was barely sharing the pain with her, as he couldn't absolutely take away everything.
Plan was feeling the pain of her body breaking, and then it was transferring to Gale. The fate lock needed a moment to take away the pain, and that moment was enough for Xiaolin to regret life.
It hardly made the pain easier as it was constant, unrelenting agony, but it surely would leave her in a better state to endure everything.