Xiao Tu's death was extremely spontaneous.
An Lin and Xu Xiaolan didn't even get a chance to rescue him before his head exploded.
The terrifyingly powerful rainbow dragon was most likely the Ancient Dragon Empress in her dragon form. The power she was unleashing now was even more formidable than what she was capable of in her human form.
Not only that, but An Lin could detect a sense of struggle in her power, as if the true intent of her divine dao had been itching to break through some sort of self-imposed shackles.
This was an extremely special type of power of the divine dao. It couldn't even be demonstrated in a tangible form, as if it was a spiritual power of the divine dao.