First, Nuova Shenron charges a spiraling, fiery energy sphere in his mouth. Then, he grabs the energy sphere and charges it in a fashion similar to the Kamehameha. Finally, Nuova Shenron raises his hands and shouts "Nova Star!" as he fires the energy sphere at the opponent, inflicting high damage through a fiery explosion.
Nuova Shenron uses this attack during the battle against Goku in his Super Saiyan 4 form, though not offensively. After Eis Shenron encases Goku entirely in ice, he demands Nuova Shenron to destroy the frozen Goku. Nuova Shenron charges up and fires the Nova Star against Goku, and it appears that he is destroyed. Fortunately, Nuova Shenron uses the heat of Nova Star to melt the ice around Goku, allowing the Saiyan to thaw out of the ice and attack Eis Shenron.
This attack seems to have variations as this move has in the original Nuova Shenron shouts "Nova Star" not only when freeing Goku from the ice, but also when Nuova pretended to be under Omega Shenron's control he shouted "Nova Star" in the Original Japanese dub, although this time the attack was used in a "lens" fashion. In the English dub, the "lens" version is given the name Nova Death Ray as opposed to "Nova Star" for the flaming energy ball.
Video Game Appearances
Under the name Burst Attack, this technique appears in Dragon Ball Z: Budokai Tenkaichi 3 as one of Nuova Shenron's Blast 2 attacks. The technique can also be used in Dragon Ball Z: W Bakuretsu Impact. In Dragon Ball Heroes is the special attack of Nuova Shenron in his Super Form, named Inferno Attack (インフェルノアタック).
In Dragon Ball: Xenoverse, it appears under the name Burst Attack and is one of Nuova Shenron's Super Skills. It can also be obtained by the Future Warrior as a reward in DLC Parallel Quest Event: "The Shadow Dragons" as part of the GT Pack 2 DLC.
In Dragon Ball Xenoverse 2, Burst Attack returns as one of Nuova Shenron's Super Skills, which can be obtained by the Future Warrior by selecting "I Want a new Super Attack!" a second time (after using the wish to obtain Flash Fist Crush). In Xenoverse 2, the Future Warrior will shout out Burst Attack when performing the technique.