Solte is a character in from Katekyō Hitman Reborn! Fate of Heat II - Unmei no Futari. He is a Ring craftsman who is able to refine Rings from either rainbow-colored stones or unknown stones. Originally a Belladonna Lily member, he deserted them when he found out their plans.
Fate of Heat II
While escaping from the Belladonna Lily, he meets Tsuna, who had just travelled ten years into the future. From then on, he puts his Ring craftsmanship at the service of the Vongola Famiglia and fights alongside them to put an end to his brother's ambition.
Fate of Heat III
Solte is only a side character, though he can help the player by creating Rings just like in Fate of Heat 2. He can be unlocked once all the Guardians have unfrozen their Rings and you can control Tsuna once again.