Majin Android 21 has a move called "Tasting Cut", which absorbs the opponent's energy and lets her use one of their moves. In the pictures you can see her using Kuririn's Solar Flare and someone else's Kamehameha after absorbing.
Her lv3 is called "Hungry Time", and supposedly works like Majin Buu's? They imply something about it might differ from his.
Additionally, her Tasting Cut is supposedly a throw move where she runs forward and grabs you, then absorbs your technique.
Source

All those comments about her wondering how "tasty" her opponents where going to be in the trailers? Yeah, looks like she was being more literal than we thought.