Although Ackster had the same skill as a previous Calamity, Trana didn't think he would become one, at least as he was now. Ackster didn't have any intentions of destroying the world, and it looked like he was just a victim of coincidence or a force greater than either of them could understand.
Since Trana now knew what kind of skill Ackster had, she also knew best how to help him grow stronger using it. She felt a little conflicted about helping Ackster strengthen the skill of a previous Calamity, especially when she didn't know his end goal. But, they had a deal, and Ackster's goal was not part of it.
So, after supplying Ackster with a mountain of precious minerals, materials, and treasures, Trana left with Ackster's Sea God Manual without asking any further questions. She was going to do her utmost to test the limits of this humanoid monstrous monster.