Burn Smash

The Burn Smash (voiced by Risako Itō) is a fire and flamethrower-themed Smash. She's actually Kasumi Ogura who is Ryuga Banjo's late-fiancé and one of the victims of Faust's experiments that got turned into the Burn Smash (バーンスマッシュ Bān Sumasshu). Her Smash essence was used as the basis for the Dragon Full Bottle.

Kasumi suffered from an unspecified illness. It is implied that her fiancé Ryuga accepted a bribe to help pay for her medical treatments, which got him banned from professional fighting. Sometime later, Kasumi was approached by Masahiro Nabeshima, who told her to direct Ryuga to Takumi Katsuragi, promising to help Ryuga make a comeback in return. Kasumi agreed, and brought up Katsuragi on her next date with Ryuga. However, when Katsuragi was found dead, Ryuga was framed for the murder and sentenced to ten years in prison.

One year later, soon after Ryuga's escape from prison, Kasumi was kidnapped by Faust. Kasumi received a call from Ryuga seconds before forcibly undergoing a transformation into the Burn Smash. Her consciousness suppressed, the Burn Smash attacked Ryuga when he came to find Kasumi. Sento soon arrived, but was interrupted by Night Rogue, who easily overwhelmed him as Build. Night Rogue gave Ryuga and Build a grim warning: due to her frail body, Kasumi was deemed a "Hazard Level 1", meaning that it would be impossible to return her to her human form without killing her in the process.

While Ryuga tried to stop Build from finishing the Smash, Kasumi's consciousness began to fight off the Smash persona, causing it to misfire when it tried to attack Ryuga. Realizing that it was too late to save her, Ryuga begged Build to end Kasumi's suffering. Using the GorillaMond form, Build was able to temporarily separate Kasumi from the Burn Smash, allowing her and Ryuga to say their goodbyes. Soon, Kasumi's consciousness faded, and Build extracted the Burn Smash's essence. The harvested essence was purified into the Dragon Full Bottle, which Sento gave to Ryuga as a memento of his beloved.

A new version of Kasumi exists in the new world. As she and her boyfriend, the new world version of Ryuga are walking, Sento Kiryu approaches them, saying that he was glad Ryuga was alive. Confused, Kasumi thinks Sento is one of Ryuga's MMA fans, and Ryuga offers to shake hands, which Sento agreed to. As Sento walks off, Ryuga and Kasumi run off to get ice cream.

Upon meeting up with Sento, the original Ryuga also mentions that he spotted the alternate versions of himself and his girlfriend.

When Killbus reactivated Pandora's Box, everyone who were directly exposed to Nebula Gas in the original World of Build regained their memories from that world, theoretically also including Kasumi.

Powers and Abilities

 * Pyrokinesis: As its name said, it has the powers to freely generate fire.
 * Fire Ball Projection: It can release fire balls from its cannons to attack its enemies.
 * Flamethrower: It can release a fire wave from its cannons to attack its enemies.
 * Retained Consciousness: Unlike other Smash, Kasumi managed to retain some of her consciousness while in her Smash form: she misfired when attempting to shoot Ryuga.

Weakness

 * Hazard Level 1: Unlike other Faust victims, Kasumi's body is too weak to survive the Smash transformation. As a result, extracting her Smash essence cost Kasumi her life.