generate concussive plasma bolts while in physical contact with his sister, carries a dagger, one long sword whose blade is a wire-guided projectile spike, and another whose hilt is wrapped in the tanned skin of his dead sister, letting him focus his mutant power through it
The Fenris Twins are not mutants, but were bio-genetically altered to gain special powers. In Thunderbolts: International Incident, Andreas revealed he was born in Madripoor, not Germany. The twins first assumed the Fenris identity in Uncanny X-Men (1st series) #200. Andreas was first seen as Swordsman in New Thunderbolts #2, and his identity revealed in #17.
Andreas was murdered by Norman Osborn in Secret Invasion: Dark Reign #1. He later resurfaced in The Illuminati #2. Baron Wolfgang von Strucker had previously made arrangements for him and his children to be cloned and resurrected by Arnim Zola. This is presumably how Andreas survived.