Otto accepts the plate (in his normal human hand, obviously). No longer occupied, the tentacles have mostly relaxed into lowered positions around his size, although the upper-right one has its claw open as if it's looking at Diana.

And - well! That stresses him a little! But he's seen Dylan in much more unsafe situations than this, so...standards are different here, he guesses. "I guess it couldn't hurt, in a place like this. Are you going to be holding classes?" For children. Obviously. Otto has no intention of learning to swordfight.