how about this.
The cure turns out not to be as AFFECTIVE as they all assumed.
Either due to sabotage, switching of the drug, or just all out failur of the drug.
They could introduce Cable and Apocolypes via the notion that Cable saved Scott when he assumed the Phoenix was his age old foe.
Rogue gains Carol Danvers' (1 of many Federal Agents in charge of protecting a Diplomat) powers when Mystique when she attempts to save Rogue from a downing plain-only to have her (Danvers) partner start seeking the mutants out when her body is found (X-cutioner her partner).
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