Played by Scott Adkins (and not Ryan Reynolds, who actually only played the pre-transformation version of Wade Wilson, contrary to common opinion), Weapon XI was a horrific movie version of Deadpool (thank goodness for next year's rebooted version). He was used in an experiment by William Stryker - an experiment that gave him the powers of various mutants. Stryker then mind-controlled him into attacking Wolverine. His mish-mash of mutant powers included Wolverine's healing factor, Cyclops' optic blast, John Wraith's teleportation/phase-jumping ability and retractable adamantium blades that were similar in nature to Wolverine's claws. Although he was ultimately defeated, it took the combined efforts of Wolverine and Sabretooth to complete the job - and, even when his head was cut off, he was still alive.
