|Title||Delfino di Pioggia|
|Size||2 - 4m|
|Manga Debut||Chapter 234|
|Anime Debut||Episode 162|
Alfin is a Rain-attribute Box Weapon with its whole body clad in Rain Flames. Its design is unique even among the Box Weapons left by Lorenzini and is considered a prototype Box Weapon furnished with an advanced communication system. Basil acquired it along with his Ring and the Book of Sukedachi in Spain after being sent ten years in the Future. The box itself has a metallic green look to it and has a black strip running along the side. The Box also has CEDEF engraved on the side, representing the Vongola External Advisory organization that Basil belongs to.
AbilitiesEditThe intelligence of the Rain Dolphin is high and it is capable of achieving mutual understanding with most Animal Box Weapons.
- Dolphin Edge: Rain Flames are gathered on Alfin's fins and are then shot forward like edged projectile Weapons. Since these Weapons are infused with Rain Flames, they can act like tranquilizers by soothing the enemy.
- Telepathy: Alfin can respond to telepathic commands from Basil.
- Brain Coating (Inter-Box Combination Launch System): Due to the high intelligence level of the Delfino di Pioggia, Alfin has the Ability to interconnect with other Box Animals, including the Vongola Box Weapons. This synchronization allows the Animals to launch a synchronized and secret attack.
- Super Nova Ocean: This attack, combining Alfin's power along with the other Boxes, was used to crack the barrier shutting off Tsuna and Byakuran's fight, letting Gamma slip through.
- Solarstorm Fang: An attack combinining Alfin's Flame with Kangaryuu's and Uri's. Kangaryuu shoots Uri with a Sun Bullet that increases its size and strength instantly, while Alfin combines its Rain Flame with Uri's Storm Flame. This results in a deadly Flame combination.
- Alfin's Box is marked "CEDEF," the organization that Basil belongs to.
- Alfin and Basil fought the Millefiore forces approximately 8 times in the 10 days that it took Basil to reach the Namimori HQ. These battles all took place before they were introduced in the Future Arc.
- Alfin's brain is shown to be coated with Rain Flames.