Even without Solaris, or the ability to use mana, Jason was still not powerless.
He had terrifically high physical strength!
Jason had no mana left which he could only circulate through his body once replenished.
Because of that, he switched Solaris with Artemis, allowing her to occupy his mana core, further enhancing his strength, while being able to manifest her wings.
Jason's veins bulged as he cleaved at the chimera in front of him.
Owing to the high speed at which Byakur was swung, faint gusts of winds swept against the chimera that was in front of him.
Suddenly, blood spurted out of its body as it was sliced into two parts.
Flapping Artemis' wings that were fully merged with Jason's body, he enhanced his speed tremendously and appeared in front of the next chimera.
He didn't even bother to look at the beast as he thrust Byakur with one hand, aiming for its heart.