Disclaimer: I don't own DBZ. Its like an alternate ending.
Trunks. Not Trunks. No. Not…. My son. He's a Saiyan… my Saiyan son…. I raised my head to the sky, looking to the high heavens, and letting out a scream worthy of five super Saiyans, and I felt power surge throughout my body. My golden aura lengthened and spread, and electricity was around me. I dashed toward Cell, and we both began to fight each other, my power nearly succeeding his. We were both landing punches on another, but I was able to kick in the face, hard. He fell back with a yell.
"T-that's it….. Fool! Final…. Flash!" Cell shouted. I followed suit, and our beams slammed into each other, sending out a shockwave that cracked the ground, sending rocks and dirt everywhere. I held the beam….. I had to kill this animal….. for…. Trunks…..Trunks…. no…. TRUNKS!
"TRUNKS!" I screamed, and my beam overpowered Cells…
Then I heard the noise of instant transmission, and I felt a hand penetrate my abdomen. My jaw dropped, I sputtered blood. The pain was unbearable, more pain than when I was hit with Freiza's death beam. I was tossed into the air, and I saw a giant beam of light come at me, and then Gohan was in front of me. His arm snapped, and I went into unconsciousness.
When I woke up, my abdomen burning endlessly, I saw two Kamehamea's battling each other….. and I understood. I had to die….. I slowly rose myself up, holding my bloody abdomen. I raised my left arm.
"BIG….BANG…" I didn't think I could do it, but I mustered all of my strength… "….ATACK!" The blue ball of energy slammed into Cells head. He turned his head…. And realized what was going to happen before it did. The force of both beams blasted him away, away from Earths, away from us. I managed a weak smile, I could feel death coming over me with a sense of finality…. I fell to the ground, and my soul left my body once more, flying to be united with Trunks…. My son…. And I died a true Saiyan.