Super Saiyan God (Version 2) is the successor to the Super Saiyan God Super Saiyan transformation, aswell as the original Super Saiyan God form. Appearance-wise, Super Saiyan God V2 has the exact same appearance as Super Saiyan God, but the power from this form is x3 stronger than Super Saiyan Blue. It's achieved by re-tapping into the Super Saiyan God power. This requires incredible control of god ki, aswell as mastery of the Super Saiyan Blue form.
Super Saiyan God V2 is the strongest Super Saiyan form to date. Vegeta tells Omegra that the form is three times stronger than Super Saiyan Blue and twice as fast. Although, Vegeta later reveals he can only hold the transformation for a short amount of time. This is due to the temporary effect of Super Saiyan God. However, users can transform into Super Saiyan God V2 at any time, but they need to be at maximum energy before they can do so.