You will see that there is a Roboute Guilliman model for the Ultramarines, but done in his colors.
And there is a Commander Dante of the Blood Angels.
So this is one of those armies that they use as a "counts as" Chapter. In a game you can only ever be one or the other. So if you play Blood Angels then Guilliman and other non-Blood Angels are not included in that battle.
It's a Homebrew Chapter.
You will see that there is a Roboute Guilliman model for the Ultramarines, but done in his colors.
And there is a Commander Dante of the Blood Angels.
So this is one of those armies that they use as a "counts as" Chapter. In a game you can only ever be one or the other. So if you play Blood Angels then Guilliman and other non-Blood Angels are not included in that battle.