Nearing completion, this cell was discovered by bulma and later, by the Androids, after breaking his cage, cell weakly tries to absorp 18, causing 18 to kill him
Cell Universe 15 Possibly it's home universe (speculation)
Because trunks does not die in the past, the Androids are deactivated beore they can find dr geros laboratory. Cells existence was never known to the z fighters and as a result, he achieves completion and leaves dr geros laboratory The first cell to attempt time travel, he encounters a weaker trunks who has never trained in the HTC and as a result, easily kills him, taking his time machine to the past, he achieves perfection and starts the cell games. His fate thereafter splits in universe 18 (death) or universe 17 (victory) currently in another universe
Warned by his future counterpart, our heroes track down and kill this cell,17 years before his completion. This happened because cell underestimated piccolo when telling him his background. Killed by krillin. Although his future counterpart later thriumps against the z fighters.