The Fusion Grenade is a weapon manufactured by Grummel Net Industries in Tools of Destruction, Quest for Booty, Full Frontal Assault, Into the Nexus, and Ratchet & Clank (2016 game). It throws grenades at enemies.
The Fusion Grenade can be upgraded to the Fusion Bomb with use.
Ratchet & Clank (re-imagined)
In Qwark's retelling, Ratchet purchased the Fusion Grenade for 100 bolts from a Gadgetron vendor as part of the Ranger tryouts on Veldin in "Head to the fairgrounds". It began as a powerful weapon with limited ammo, that Ratchet could upgrade with Raritanium upgrades. With use, the weapon upgraded to the Fusion Bomb. In the film, Ratchet practiced with an individual grenade as part of his training.
In challenge mode, the weapon may upgrade to the Omega Fusion Bomb for 130,000 bolts, once the Fusion Grenade's holocard set complete. The set contained the Fusion Grenade, Bouncer, and B6 Obliterator cards.
Tools of Destruction
A Fusion Grenade is the next generation of explosive bombs, now designed to burst in the air instead of the ground
Survival Guide Weapon Description, ToD
The Fusion Grenade was one of two weapons Ratchet began with, along with the Combuster. It began as the most powerful weapon (dealing 150 damage with each grenade), though with limited ammo. Its bombs did not explode on contact, but a second after being thrown. It could be upgraded with Raritanium, such as with more damage, bigger area, more ammo, more bolts, and its special upgrade, Concussion Detonators, which knocked down enemies not killed for longer.
With use, it upgraded to the Fusion Bomb, adding GrummelNet's patented "Intelli-Seeking Pyrocidic Nitroballs" to each grenade, launching bomblets after exploding. In challenge mode, it may upgrade to the Omega Fusion Bomb for 6,500,000 bolts.
Quest for Booty
The Fusion Grenade was a weapon Ratchet started with at level 3, but lost in the Azorean Sea when Rusty Pete launched him and Talwyn to Hoolefar Island. Later, Pete returned it and the Combuster to Ratchet after reviving Slag and Darkwater in Morrow Caverns. As with the previous version, its bombs exploded a second after being thrown.
The Fusion Grenade still upgraded to the Fusion Bomb with use, though this upgrade did not add bomblets to each grenade. Instead, the Concussion Detonators upgrade had to be found first. Ratchet acquired it in the underwater tunnel on the bay of Hoolefar Island. He had to dive into the bay and enter the underwater tunnel, jump out of the water, smash crates, and blow down the gate to acquire it.
Into the Nexus
The Fusion Grenade was obtained when re-entering the Nebulox Seven Prison Ship after Vendra Prog had disrupted gravity. It had a vastly different appearance. Unlike previous appearances, its bombs exploded on contact with a surface. At level 3, it upgraded to the Fusion Bomb.
The Fusion Grenade and Fusion Bomb are both wrist-mounted gloves. They have a blue, bulky design with a large node on the back. In Into the Nexus, the design is completely yellow, and less bulky.
The Fusion Grenade tosses bombs at enemies which have a decent area of effect and deal strong damage. Early on, its damage is very powerful, making it useful against most bosses and tougher enemies. However, as an early weapon, it is easily outclassed by weapons acquired later on in damage and in area of effect. Much like the Combuster, it transitions to a weapon used to spread damage across a large area, rather than fight single targets.
The Fusion Grenade in Ratchet & Clank and Tools of Destruction can be upgraded with Raritanium, adding upgrades such as more damage, ammo, area, and bolts acquired. The player should probably aim to improve its area and ammo first, to help it transition later, though improving its damage can be helpful. In Tools of Destruction, the Concussion Detonators upgrade and the Fusion Bomb make it far greater at dealing with groups of enemies clumped together, and after this point, that is how the Fusion Bomb should be used primarily.