This is the most powerful, most devestating, most awe-inspiring weapon that can be crammed on a bomber. A single Helios antimatter torpedo has several times the destructive payload of the GTM Cyclops. The large weapon is so expensive and dangerous, that its issue is limited only to those who have been given special authorization by the GTVA Security Council.
A Helios torpedo is even slower than a Cyclops, making its effective deployment difficult. As with the more common torpedo, range is everything: you don't want any. Get in close and make your shot count. Due to the Helios' slow speed, it is advised to engage your burners BEFORE you release the weapon and being your evasive maneuver. This will give the torpedo some badly needed speed as it crosses the (hopefully short) distance to the target.
Puzzlingly, the GTF Myrmidon space-superiority fighter has the ability to mount a Helios torpedo in one of its bays. It is unknown whether this was a very quiet design feature, or an interesting quirk of fate.