Board Thread:News and Announcements in game/@comment-27996636-20171208091053/@comment-30340667-20171209101206

Can't confirm anything yet, but I found a tiny hint. Look:

it really depends on what his arms are doing. Look at the Vegito art in the Manga panel. He is firing a Ki blast, with one hand bent behind himself. The arm to the right of the Dokkan art, could be the stationary arm, if the other arm in the full art is firing a Ki blast.