Basil acquired it along with his Ring and the Helper's Book in Spain after being sent ten years in the Future. Alfin and Basil fought the Millefiore Famiglia forces approximately 8 times in the 10 days that it took Basil to reach the Vongola Underground Base.
The Delfino di Pioggia is highly intelligent and is capable of achieving mutual understanding with most Animal-type Box Weapons. It can communicate and coordinate with other Animal-type Box Weapons to deliver complex combination attacks.
- Dolphin Edge: ((ドルフィネッジ, Dorufin Ejji?)) Alfin sends out multiple projectiles shaped like edged weapons. Since these projectiles are infused with Rain Flames, the targets will receive effects of the Tranquility characteristic.
- Dolphin Pulse ((ドルフィンパルス, Dorufin Parusu?))
- Special Attack ((特攻, Tokkō?))
- Swimming Blade Dance ((泳舞斬, Eibuzan?))
- Telepathy: Allows Alfin to respond to telepathic commands from Basil, with its SS-ranked intelligence playing a factor in this as well. The Rain Flames covering Alfin's brain boost this ability.
- Brain Coating: Alfin's high intelligence level allows him to interconnect with other Animal-type Box Weapons, including the Vongola Box Weapons. This synchronization allows the animals to launch synchronized and secret attacks, and makes even combined Dying Will Flame attacks such as Solarstorm Fang or Super Nova Ocean possible.
- Super Nova Ocean
- Solarstorm Fang