ers , ▁and ▁effectively ▁er ased ▁from ▁a ▁series ' s ▁continu ity . ▁Later ▁stories ▁may ▁contradict ▁the ▁previous ▁ones ▁or ▁explicitly ▁establish ▁that ▁they ▁never ▁happened . ▁ ▁A ▁notable ▁example ▁of ▁subtract ive ▁ret con ning ▁is ▁the ▁X - Men ▁film ▁series . ▁The ▁ 2 0 1 4 ▁film ▁X - Men : ▁Days ▁of ▁Future ▁Past ▁features ▁the ▁character ▁Wol ver ine ▁travel ing ▁in ▁time ▁to ▁ 1 9 7 3 ▁to ▁prevent ▁an ▁assass ination ▁that , ▁if ▁carried ▁out , ▁would ▁lead ▁to ▁the ▁creation ▁of ▁a ▁new ▁weapons ▁system ▁called ▁the ▁S entin els ▁that ▁threat ens ▁the ▁existence ▁of ▁mut ants ▁— ▁and ▁potentially , ▁all ▁of ▁human ity . ▁The ▁events ▁of ▁this ▁film ▁ret con ned ▁those ▁of ▁two ▁previous ▁films ▁in ▁the ▁series : ▁ ▁X - Men : ▁The ▁Last ▁Stand ▁( 2 0 0 6 ) ▁The ▁film , ▁a ▁loose ▁adaptation ▁of ▁" The ▁Dark ▁Phoenix ▁S aga " ▁from ▁the ▁Un c anny ▁X - Men ▁com ic ▁book ▁series , ▁featured ▁the ▁un cer emon ious ▁death s ▁of ▁select ▁key ▁characters ▁( including ▁Cy clo ps ), ▁trigger ing ▁a ▁mixed ▁fan ▁response ▁from ▁those ▁who ▁felt ▁the ▁death s ▁were ▁sudden ▁and ▁under - expl ored . ▁Days ▁of ▁Future ▁Past ▁er ased ▁these ▁death s ▁and ▁the ▁characters ▁are ▁shown ▁to ▁have ▁surv ived ▁at ▁the ▁end ▁of ▁the ▁film . ▁" The ▁Dark ▁Phoenix ▁S aga " ▁would ▁subsequently ▁be