Kokusho is the most famous of the five legendary Dragon Spirits, and its effect scales up well for multiplayer games, too, while the same can't always be said for its counterparts in other colors
Not to mention the inclusion of ex cards
Second, any damage on the old character sticks around, like an unwanted guest at a party
Obscuring Aether lets us start playing morphs on turn 2, but it starts getting really crazy if were drawing extra cards with Secret Plans, often producing an effective three mana a turn
Part of me wants to tinker with the deck, though, and its likely to be plundered for parts for either Iroas or Aurelia, the Warleader
It is quite simple so it doesnt offer a lot of flexibility and if your opponent has a counter, then you are stuffed