The main antagonist in the film Final Fantasy VII: Advent Children
. Just like his two "brothers" Yazoo
, he is born of the lifestream
and made from "remnants" of Sephiroth
-and possibly Cloud Strife
(because of Cloud's time spent in the lifestream), hence the reason he calls Cloud big brother.
*Warning- Crisis Core
But, some theorise that he is actually the degraded Genesis
, from Crisis Core and that the two strangers who picked him up at the end are Loz and Yazoo
He fights with his "Souba", a double-bladed katana.
As he is made from the lifestream, which is why he can absorb Jenova
's cells to turn into Sephiroth
Kadaj: "You see this man, he's our big brother. But alas, in our happy flock, he's what you'd call a black sheep."