Onyx did focus herself on keeping upright, but that only briefly delayed her retaliation. She managed to turn and put her back to him, then grab his arms. If one of his arms was still free, he could have used the position to get a tight hold around her, but as it stood, she had his arms and was clawing at his wrists. Certainly, it did hurt, but Tarentek's scales were thick, perhaps more-so than Onyx expected. Against a forceful stab or slash from a knife or other blade, his scales could not hold up, but his natural armor was reasonably effective in hand-to-hand combat. When she slammed into him to knock him down, he did indeed start to fall, but he had managed to keep his grip on her arm, so he was pulling her down with him.

Tarentek prepared for the impact. If Onyx was thrown off enough by the fall, then he had a good chance of getting his arms around her and forcing her into a situation where he had much more control. Grappling on the ground was where his strength would really shine. If she came up with something creative, however, he could lose control, and likely wouldn't gain it back. He did not currently have the endurance to sustain an extended fight.