Storm first encountered Karima on the streets of Cairo. Like Ororo, the yound girl and her friend, Jamil, lived under the tutalage of master thief Achmed El-Gibar, but Jamil's anger led him to leave the "family" and follow the Candra.
The External surfaced later with Jamil as her acolyte and Karima as her hostage. Candra sought her heart-stone and discovered through Jamil that Ororo had stolen it. It was during this battle that Storm realized Jamil was only a figment of Karima's imagination and a product of her power.
Karima was a police officer from India who was transformed into an Omega Prime Sentinel by Bastion of the Operation: Zero Tolerance program. It all started when Karima was dispatched to look after Neal Shaara (who would later become known as Thunderbird). Neal was looking for his brother, Sanjit, who had gone missing researching some mysterious disappearances in Calcutta. A bond quickly developed between the two, and they were on the verge of beginning a romantic relationship when they were attacked and captured by Bastion. Neal learned that Sanjit had become a Prime Sentinel, programmed to seek out and destroy mutants. Bastion intended to do the same to Neal and Karima, but the morphing process catalyzed Neal’s latent mutant power, which destroyed the building around him. Sanjit fought his programming long enough to disable the other Sentinels, but died in the process.
As Neal cradled Sanjit’s body, Karima quietly told Neal to run. She had discovered that she was a Prime Sentinel; humans transformed into sentinels and set up as 'sleeper' agents, unaware of their programming until a nearby mutant activated them (as in Neal's usage of his mutant powers).
"I am an Omega Prime. Within moments I will have reached my full combat mode–with my core programming to destroy creatures like you. It is becoming increasingly difficult to even think of you as human. Your only chance is to disappear. Get as far away from India – and from me – as you can. Assume a new identity... a new life."
Neal refused, saying he loved Karima. Karima begged him to leave, saying she couldn't hold on much longer. Neal was forced to flee.
Karima later resurfaced on the decimated mutant homeland of Genosha, where she encountered Charles Xavier and Magneto. The two were able to disable her Sentinel programming and restore her mind, but the technological modifications to her body remained.
Karima stayed on the island with the others, working as a police officer to restore order. She is trying to adjust to her new form, which comes into conflicts with her Hindu beliefs. It is assumed she left the island with most of the other residents after Decimation.
Karima Shapandar (by Marc Silvestri)
Karima Shapandar (by Marc Silvestri)
The X-Men recently discovered a disassembled Karima, along with Lady Mastermind in a lab of the Fordyce Clinic that was testing on mutants to see if someone can catch mutation like a disease. As of X-Men #189, Beast has reassembled her. But she appears to have lost part of her memory from the moment she got disassembled. In issue #192, Rogue officially recruited her onto the team to help fight the Children of the Vault.
Since then she was able to help fix a teleporter in the search to find Pandemic, helping in the fight to defeat him. After Rogue was infected with a virus by Pandemic and Cable took the team to his island so Rogue could be cared for. On the island, Karima helped the team and the island residents who were attacked by the Hecatomb.
Omega Sentinel is possessed by Malice, who is now a digital entity instead of a psionic one, via email virus; thus, she unwillingly ends up joining the new Marauders in X-Men #200. Whether being part machine and part human will allow her to overcome Malice's influence has yet to be seen. The other X-Men, save Emma Frost, are unaware of her being possessed.