I thought that Loki would be impressed by Mobius' rage, or that he would be amused. Or that he would immediately start torturing Brad as soon as Mobius got out of the cell.
But no: Loki was stunned by Mobius' reaction.
So, at first, he took steps to stop Mobius before he went too far and escorted him away safely.
Then he followed Mobius to make sure he was okay, asking him over and over without using aggressive tones, despite Mobius trying to downplay it.
Loki saw that Mobius was trying to hide how shaken he was, so he suggested to eat a slice of pie to reassure him down.
Without pressure, he calmed him down until Mobius was ready to open.
And then he reassured him gently.
This shows how much Loki has changed: instead of being overwhelmed by anger and the desire for revenge, he put the well-being of Mobius, a person dear to him, first, without hiding the concern and affection he feels for him. And Mobius, in return, demonstrated that he placed full trust in Loki, expressing his innermost emotions to him.