So I was looking through the notes in ddd and found the fact that keyblades have one of three cores: light, darkness, and heart. After i dug
around on the computer i found that only one keyblade of heart was made. ASoD made one in kh1 out of 6/7 princesses of heart but he
was short one heart (kairi's) and so it just dissolved and he couldn't finish it. Anyway what I'm getting at is a keyblade of each core is
needed to get into kingdom hearts meaning that another keyblade of heart will need to be made for the 13D or 7L to enter kingdom hearts
which implies that either the 7 pure hearts ( either kairi's or Ventus ) or some other way of making a keyblade of heart will be need for
kingdom hearts to be entered. Or maybe we will explore the realm of heart that you go to in the beginning of almost every game.