The change doesn't bring much of a change to Robin's expression, but his eyes do slide towards Tonic, whose expression has changed to that of blatant surprise.

"Oh," is the man's first reaction, followed by a measured silence as he absorbs the gravity of the situation. Robin has brought him something very dangerous, which he more-or-less understood, but the extent of it has finally sunk in.

And Robin knows this, too. He's actually taken a fairly big risk, bringing Phalanx here. The only reason he's so calm about this is because he knows he can destroy Tonic faster than Tonic could get the word out about Robin's new friend.

"So you like the skirt, Phalanx?" Robin asks them, pretending that all of that background noise isn't happening and beginning to grin, "It fits?"