Of all the new rainbow rarity weapons and items in Borderlands 2, one of the most nuanced to get is the Unicornplosion shotgun, as it ties together the infamous Butt Stallion, Tiny Tina's Assault on Dragon Keep, and the new Commander Lilith and the Fight for Sanctuary DLC.
In a manner similar to the Swordplosion shotgun, this weapon fires explosive Butt Stallions instead of the typical shotgun spread. It's a good rainbow weapon to have when facing the various baddies in Borderlands 2, so here's how to get the Unicornsplosion Rainbow shotgun.
Complete "The Amulet" Side Quest
While there are two sidequests related to this Borderlands 2 rainbow weapon, it does not matter in which order they are completed, but one quest that is required to get the Unicornsplosion is "The Amulet" from Tiny Tina's Assault on Dragon Keep. The reward for doing the side-quest is a mysterious amulet that, up until now, had no real purpose in the game.
To get the amulet, players will want to fast travel to the Lair of Infinite Agony in the Tiny Tina's Assault on Dragon Keep DLC. They must buy the Amulet from a mysterious figure known as Mr. Miz (and not choose the "punch in the face" option). However, Mr. Miz has a low spawn rate, so this requires players to save and quit repeatedly until Mr. Miz spawns in the area. Simply check the Borderlands 2 map for the yellow exclamation point until he appears. Players who already have the amulet may obviously skip this section.
Complete "My Brittle Pony" Side Quest
One of the new side-quests in Borderlands 2's Commander Lilith and the Fight for Sanctuary DLC is "My Brittle Pony," which unlocks some time after getting access to the Helios Fallen area. Completing this quest will see Butt Stallion appear in the Backburner, in a manner similar to her appearance in Tiny Tina's DLC, and players will be able to feed her in order to get weapons, too.
How to Get the Unicornsplosion Rainbow Shotgun
After completing the two aforementioned quests, Borderlands 2 players will simply need to get the Amulet and feed Butt Stallion some Eridium. Doing so guarantees the spawn of the Unicornsplosion, and if in a co-op game, it's worth mentioning only one Amulet is required. Others should be able to feed Butt Stallion to also receive the weapon without having the Amulet, but only one will spawn for each player.
Borderlands 2 is out now for PC, PS4, and Xbox One.