The Extingus Breath ability was like a forcefield for Timothy, except it wasn’t as strong as Ortana's force fields so he had learned not to depend on it. This ability mainly featured a blue mist, a cloud of sorts, so it wasn’t exactly physical.
This ability was meant to dissolve attacks, more than it was to stop them dead on the spot. If he breathed out a bigger, and wider Extingus Breath, the cooperative blue cloud would be able to dismantle even bigger attacks, which was advantageous, but he hadn't fully figured out what this ability was capable of, so he'd rather proceed with caution.
“Might as well buy it since it can protect me from evil shit, then! It doesn't cost anything to cast it either, so I could really use it.” He said.