In the series we see Toru activate his power every once in a while. And also disabling it every once in a while. The fact he disables it makes me wonder, do his powers have any side effects ? What exactly are his powers anyway?
Iron Blood Transformation: A saboteur technique, activated by extreme mental concentration, that optimizes and redefines the user's entire body systems. This allows Toru to perform inhuman physical feats, such as repelling a feira unicorn or jumping several meters into the air. The transformation also substantially improves his combat skills and techniques, allowing him to fight against high level opponents. A drawback to using the Iron Blood Transformation is that the technique requires a huge amount of energy. When Toru transforms for the first time in a very long time, he needed a huge amount of food to restore himself or risk fainting. Another drawback is that it makes him more susceptible to poison, as the technique improves his respiratory system which would increase the flow of any poison inside him. In the anime, his hair turns red and two crimson streaks cross over his face while emitting a red aura during the transformation.
Source: Hitsugi no Chaika wiki