Liszt was well-grounded.
Not only did the Smoke Mission act as a golden crutch, allowing him to harness the power of fate even in a Mind Battle, but he also now possessed a Phoenix Incarnation. He had tried it; within the spirit of a dragon, the Phoenix Incarnation could still be used, and its power was formidable.
With the help of the Phoenix Incarnation, he was absolutely going to call the shots in the Mind Battle.
As long as the requirements of the Aluminum Dragon's Mind Battle weren't as quirky as those of the Formless Dragon, he wasn't afraid of not being able to win—most dragon Mind Battles were primarily about brute force, with other requirements playing a supporting role; only the Formless Dragon's was mostly about navigating a maze, which had caught Liszt off guard.
That's why he agreed to give Florenza Chase Wind Arrow a chance at a Mind Battle, letting Florenza get a taste of the Aluminum Dragon's Mind Battle requirements first.