Jason almost expected the defensive response from Clarence, the debris burning away with the sizzle of disintegrating rock. He never expected Clarence to get hit, of course, but this was a prime chance to see what the man is capable of when dealing with the unexpected. He's good, at least, better than some opponents Jason has done battle with.
Don't reform yet, Jason idly comments to his Familiar, who gives a patient affirmative in response. They both need to wait for the best opportunity for the dragon to re-materialize or there will have been no point to the last few exchanges. The issue, at its core, lies in the fact that neither of the combatants can close in- Clarence has no idea where his enemy is, and Jason is aware enough to realize attacking Clarence directly may well be suicidal. He doesn't know how injured Mimring is, after all, and won't until the dragon reforms. And that reformation would best happen at the correct time and in the correct circumstances.
So what to do?
What a pain, the dragon complains, to which Jason internally grins.
More worrying than the sizzling sounds of Jason's attack failing, a quick glance at Clarence tells the Shapeshifter that the man is surrounding himself with azure fire. The very same as the flames licking the battlefield around him, it seems. If the general room temperature and Mimring's own blue flames are anything to go by, Jason would hazard a guess that the fire burns cold, but this is something he cannot be sure of and isn't exactly willing to test out firsthand. At least not when his own fire in his dragon form burns blue and incredibly hot.
The other thing Jason notices is Clarence's actions in these last few seconds. Rather than try to attack an unseen enemy, he seems to be... attacking whatever structures are in reach? The Shapeshifter isn't certain if this is a further effort to uncover Mimring's nonexistent hiding place or an attempt to intimidate in a display of power, but an idea pokes at the back of his mind regardless. How much abuse can this chamber take? Did ancient Egypt account for a battle to the death occurring here between creatures of great power? And so a plan forms in the Shapeshifter's mind, and as uncertain of its outcome as he is it's worth trying regardless.
I have an idea.
An already-prepared magnetic charge intensifies, the rubble Clarence had been throwing around reacting to this new impulse. The charge trickles into the floor beneath them, magnetizing patches of ground to Jason's will. The Shapeshifter takes but a few seconds to prepare before taking his idea into action- the floor's charge polarizes to match the rubble, and the debris flings itself from the ground once more. This time, however, they are not directed at Clarence- seeming to avoid him entirely, in fact, and instead aim for the pillar closest to him and the ceiling above him. Impact would severely damage both projectile and structure, and with Clarence's own efforts may cause the pillar, at least, to crumble, if not even crack the ceiling above.
Jason may not know what Clarence is planning, but he knows how to adapt and adjust it to his advantage.