The Hydra is a missile launcher meant for enemies 20meters and longer, primarily by using the scope. It takes 2 shots to kill an enemy with full shields, giving you 3 kills on average.
When using the scope, you can lock onto enemies by having the reticle over them. Once locked, the missile will follow the target when you shoot it.
The missile will have a delay before following the target. When enemies are behind cover, shooting upwards allows the missile to arc over cover, and killing him. This one of possible tricks you can do to deal with opponents.
If the enemy is closer to you, the best is to aim at their feet. Be aware that this isn’t the best range to use the hydra. If you really want to use it, stay back to utilize it effectively.
Recap:
Mid-Long range power weapon
Locks on using scope
Can make missiles arc when locked to a target and pointing the Hydra away from target.
Not so good at close range.