Antiform is a mechanic to stop players from abusing the drive form. It's a reference to Sora turning into a heartless, but not necessarily a progression or evolution of his darkness. Technically, you can play through KH2 without ever activating Antiform.
When did Sora become a nightmare? Are they referring to Ventus' armor?
The coded part is a huge reach also...
Dream Drop Distance is the only time in which Sora is actually getting "worse." This is almost strictly, in my opinion, to make Riku look better in comparison. Prior to Terra's existence in the series, Riku's journey was a foil to Sora's own. Now, however, it seems like everyone has to be a foil to the failure that is Terra. Everything Terra did wrong, someone else has to do right.
When did Sora become a nightmare? Are they referring to Ventus' armor?
The coded part is a huge reach also...
Dream Drop Distance is the only time in which Sora is actually getting "worse." This is almost strictly, in my opinion, to make Riku look better in comparison. Prior to Terra's existence in the series, Riku's journey was a foil to Sora's own. Now, however, it seems like everyone has to be a foil to the failure that is Terra. Everything Terra did wrong, someone else has to do right.