Eli has added some awesome new slugs to his arsenal: the ELEMENTALS. But the Elemental Slugs are ancient, extremely powerful, and temperamental, and Eli can't control them. Junjie, the newest member of the Shane Gang, has the solution: Eli must learn SLUG FU, the ancient form of slugslinging that Junjie mastered when he lived in the Eastern Caverns. Slug Fu is the art of guiding and controlling a slug in battle—a skill that only the greatest slugslingers can master.
Eli has added some awesome new slugs to his arsenal: the ELEMENTALS. But the Elemental Slugs are ancient, extremely powerful, and temperamental, and Eli can't control them. Junjie, the newest member of the Shane Gang, has the solution: Eli must learn SLUG FU, the ancient form of slugslinging that Junjie mastered when he lived in the Eastern Caverns. Slug Fu is the art of guiding and controlling a slug in battle—a skill that only the greatest slugslingers can master.
But while Eli and Junjie train in isolation, separated from the Shane Gang and all of Eli's slugs, a mysterious new villain named Spirex unleashes an evil plan that will rock Slugterra to its core! All he needs to complete his plan are the Elemental Slugs! Luckily, they're safe with the Shane Gang...or they would be, if Pronto hadn't annoyed them so much that they ran away. As Kord, Trixie and Pronto struggle to keep the wily Elementals out of the wrong hands, Eli and Junjie engage in a showdown with Spirex before he can reduce the 99 caverns to rubble!
Shinai, The unbeatable master of slug slinging had a fight in a hotel. The
Shane gang were passing and Eli meets her.Trixie mentions that she is the unbeatable master. She then leaves the hotel. The very same night, the gang talk about her and want to get some training from her. Eli was very eager that he left early in the morning to her home. He was surprised to see a lot of slingers who wanted to get trained. She helds a competitions in which a majority slingers were disqualified. But they refuse to leave. So she performs the legendary fusion shot using her slugs, Sonikin and Inkdevil and throws them out. She held a tournament and whoever wins gets trained from her. Twist comes in a disguise. Twist and Eli go to the finals. An hour before the finals, Eli talks with her that Twist shouldn't get trained from her. She tells a flashback that Will Shane and Blakk came to her. She trains he one who wins in the duel. Will wins and gets trained. Blakk become enemy to Will and starts experiments with Ghouls. Will could've known the secrets of slugterra even without her help. She feels guilty that Blakk turned evil because of her. When Eli and Twist were about to duel, Blakk interferes with some soldiers, a bull mecha and a new gattling blaster. Sinai duel Blakk, Eli duels Twist and the gang duels the soldiers. When Twist is defeated, he flees but disguises as Blakk and fights with Shinai. She defeats him using the fusion shot and the disguise wears off. Blakk kills her by shooting a Boon Death (Ghouled Boon Doc) at her on the back. Eli asks help from his Boon Doc but it was of no use. Eli uses his blaster and defeats Blakk by performing a fusion shot with Burpy and Joules. Blakk leaves the place while the gang feel sad about her death. Even her slugs also go with her.
Eli and his gang have to stop a drill that is in an underwater cavern.
Danna uses the device she stole from the treasure chest to teleport from one place to another and becomes a thief. She steal things from everyone, even Trixie's camera. By mistake, she steals Blakk's blaster. So Blakk appoints a Gentleman to get his blaster and Danna alive.Gentleman is an experienced slinger who uses Geoshard slugs to crystallize his opponent. Knowing this, Eli tries to save her from the gentleman. The gang blackmails him to change the plan. When he confronts her he duels her. Blakk and Eli come later to the duel . Gentleman shoots her in such a way that she doesn't get crystallize completely. The crystallized Danna falls into a river. Eli saves her and escapes. She gets cured using Pronto's Slyren. Eli thinks that the device will be safe with Danna.
Lumino Cavern has been invaded by a swarm of Neurotox ghoul slugs that have created a toxic cloud that’s attacking the residents. The Shane Gang must brave an inescapable maze to locate Blite, the only man who can help them.
Eli and Kord have been trying to create a fusion shot which consists of two slugs being shot at the same time using both of their powers. In order to make it work, they’ll need to travel to Scrap Heap, a junk yard cavern protected by Boss Ember and his Scrap Force.
Eli and the Shane Gang become trapped in caverns underneath SlugTerra and discover a new type of danger that is threatening to escape.