You could emulate it.
Make a particle effect which is supposed to last X seconds with a charge up like animation being part of it.
Then create a sound effect reflecting that animation.
Make the weapon having a decently long cooldown.
Then add it all to the weapon slot it is meant for.
Suffice to say it would probably be some sort of burst damage weapon with fairly low DPS overall.
As an example you could take the Vulkoras' bombardment platform as reference I guess.