COMPOSITE EVERYONE IN NARUTO, BLEACH AND ONE PIECE UNIVERSES AT THEIR STRONGEST FORM LITERALLY AT THE SAME TIME.
Cuz there are immortals here and there, so even if cell busts the solar system is doesn't matter OP didn't specify but I'm assuming it's when everyone's dead and well, you can't kill immortals now can you? And it's everyone at the same time? LOL hope he doesn't get haxed before then.
@yasindermann: HST refers to the big 3( holy shounen trinity), bleach, naruto and one piece. Jojo isnt part of the HST. Btw i've meaning to watch jojo for a long time, to watch "diamond is unbreakable" do I need to watch the previous parts???
Don't bother watching any of Jojo. Just read it. If you watch you'll drop, if you read it's much better, it's still not that good but better. Only certain parts are good but if you just skip around you'll miss important stuff, not that improves the quality of Jojo any but you'll just be confused.
TL;DR if you wanna get into it read. If you don't, then watch. Don't start anywhere except the beginning. Beware there are only a few good parts either one you choose.