The Primordial Beast's words did not make Rowan stop his actions. If Bahamut was bluffing and he froze as a result, then his defeat would be too pathetic. Just because this was a ninth-dimensional entity did not mean his talent for deceit was lesser; instead, it was most likely the opposite.
It also helped that among the most negative outcomes from this battle that may arise, Rowan had considered that other Primordial powers might be included as it progressed forward. As far as he could tell, there had not been any fight of the level in the Supreme Era, and no matter how durable space was to be, slight traces of their battle were still escaping from it.
The thing was that, even if the Primordials arrived, Rowan would simply deal with it as best as he could. There were methods he had placed down that might ensure his survival, but in battles of this level, he was never a hundred percent assured of its outcome.
