Stryker was killed by Elixir's organic power in new X-Men (2nd series) #27. He was reanimated by Bastion and his techno-organic virus in X-Force (3rd series) #3. He was killed again when Archangel sliced him apart in New Mutants (3rd series) #12.
Stryker was brought back as a cyborg prior to Weapon X (3rd series) #1-3. It was later revealed he made a pact with the Devil to return from Hell, accounting for his survival.