Tremain was a mutant captured and studied by the Mandarin. On a secret mission, the Six Pack attacked the secret base Tremain was held in. Tremain had severe injuries, and Cable tried to save him. Cable used his telekinesis to keep Tremain's body together, but was forced to give him a blood transfusion. Although he survived this trauma, Cable seemed to think Post had later died.
Years later, Tremain resurfaced as Post, the lowest of Onslaught's emissaries. Onslaught forced Gateway to teleport Cyclops, Storm, Iceman, and Wolverine to where Post could 'test' them. The four managed to defeat Post and were transported back to the Mansion.
Tremain was a mutant further altered by his exposure to Cable's techno-organic virus, possibly by the Mandarin, and lastly by Onslaught.
Superhuman Strength: He seemed to possess enhanced strength, the likes of which never properly gauged. Exposure to Cable's techno-organic laced blood possibly enhanced it to further levels.
Superhuman Durability: Post also possessed heightened once being able to resist the combined assault of Storm, Cyclops and Iceman and recover almost perfectly unharmed. An aspect that was also; suspectedly, enhanced by T-O Virus intake.
SCULPTED AND PAINTED BY TOYMAN ARTIST SANNY ALOJADO BLANCA!!!!