Destroy a Vault Robot Fusion Guide

Last updated 2026-10-08

Progression

Fusion needs four robots of the same type and access to the second island. Combine the matching set there to get a stronger robot. A fused robot cannot be fused again in the system described by the current beginner guide.

1. Unlock the second island from the island prompt.
2. Keep four matching robots of one type.
3. Go to the fusion station on that island.
4. Select the matching set and inspect the output before confirming.
5. Place the stronger result into an available slot so it joins the army.

Why matching duplicates matter

AlphaShoe’s later island visit describes “four of the same” combined into a Mega robot. The Bloxodes guide independently explains the four-matching-robot input. Different robot names are different types for this step: a Crossfire, an Ironclad, a Cobra and a Phantom are not four Crossfires. A repeated roll can therefore have a use even when it does not improve your Index.

Keep the inputs you intend to combine. The gameplay includes removing weaker robots and using a trash control, so deleting a duplicate is a real inventory choice. Before clearing out a duplicate, compare it with your fusion set. If you already have three matching robots and island two is unlocked, the fourth matching result serves a specific purpose beyond its individual damage.

Unlock cost and progression context

Superlex’s recording shows an island prompt at 700,000 Cash. AlphaShoe later quotes 60 million for the next island after encountering fusion. The two observations refer to different expansion positions. Your current island prompt supplies the purchase you are about to make; the 60-million figure is not the cost of every island or an extra fee for each fusion.

Smelt Gold into Cash before saving for an island. Avoid spending all your Cash on more roll positions if the next required step is an island unlock or a robot purchase. The currency guide explains why Gold, Cash and Gems have different spending paths.

Fusion and mutations solve different problems

Fusion consumes a matching robot set to make a stronger result. A Mutation Core is bought with Gems at the Market and applies a modifier to a robot you choose. They are separate menus and resources. The present collected material does not provide a universal fusion multiplier or a current mutation multiplier table, so compare the live output and damage display for your chosen robot.

A stronger result still needs to be placed. Owning the fused robot while every slot is occupied does not automatically replace your weakest army member. Check the old robot’s displayed DPS, make room, then equip the result. If the old robot is one of your future matching inputs, remove it thoughtfully rather than treating every removed robot as disposable.

Start with the robot reference to identify the matching name, then use the progression decision guide for the island and slot purchases around fusion. Players who have not yet made a stable earning base should complete the first Cash cycle first.