If Bastion's currently augmented defensive abilities gave out before substantial progress could be made, the situation would become precarious.
Though Kieran possessed new skills of unknown power, he couldn't ignore the fact that Bundal far exceeded him in STR.
Furthermore, because of Hekaina's skill, Kieran was apprehensive about using Deranged Spirit. What if Argexes' Blood reacted outside of his expectations due to its inherent dislike of Hekaina and the power she wielded?
What could this mean for the Archaic Verity Compendium in his soul? Could there be conflict between the blood flowing through his body and the item embedded in his soul?
Regrettably, these were questions that required time, effort, and stringent examination, all of which Kieran couldn't afford to spare given his current situation.