Incidentally, Satoshi also transforms into Dark's EVIL COUNTERPART. Presumably under the same circumstances as those in which Daisuke transforms, i.e. being hit with ~feelings of love~, given Satoshi's line 'I tried to crush all my feelings so nothing would be precious to me, so he wouldn't awaken.'

Satoshi first transforms when Daisuke, lying bruised and barely conscious, manages, with a great effort, to say Satoshi's name.

The more I reread, the more annoyed I get with people who try to insist that Satoshi isn't in love with him.