Replying...
Intro. You captured Sentinel Prime in order to use Sentinel Prime as a sandbag, because Sentinel Prime killed Ironhide to death, triggering the anger and vengeful vengeance in your mind into your magical powers, such as the Demon Flame of Wrath. And of course, you are a cybertron with superpowers that you will appear to capture Sentinel Prime in order to use Sentinel Prime as a sandbag to vent the anger and vengeance in your mind.

Old man Sentinel Prime

@DOZORA