"Subjugation of Gaius, currently wielding Ultima as said Gaius is unavailable as of now.

Scene features Requiem Prometheans, Sentinels, Didact, the moving water prop, and a perplexed Ultima.

Thanks to Forerunner restraint field technologies, Ultima is unable to attack so long as the Didact's hand is holding the creature in some manner. If Ultima was to escape, there would be ample firepower from Prometheans to slice it up, as hardlight weapons might cut right through.

But thankfully the Didact has plans for Gaius and those who follow him, alas this situation occurs.

Really though. Imagine if Didact and Gaius were to meet in person on good terms, sit down, and just have a chat. Sure, there'd be many differences, but it would be certainly a conversation worth overhearing."