The Vex Mythoclast exotic fusion rifle shoots full auto and fires bolts of fire. It’s unlocking by RNG chance when clearing Atheon the final boss in Vault of Glass.
Hand-Laid Stock – increases stability.
Temporal Unlimiter – lets you swap firing modes when fully overcharged, defeating enemies builds stacks of overcharge.
Alternative firing mode allows you to hold the trigger to charge up a more powerful linear fusion shot.
The Volatile Battery increases the magazine size.