I'm not entirely sure as I haven't read it specifically. But generally, it might be about a black obelisk which could be a central mystery, a symbol, or an object around which the story's plot, characters, and events revolve.
Another possibility is Heimdall. As the all - seeing guardian of the Bifrost, he would be aware of Odin's situation from the start. He could be the one trying to piece together what happened to Odin and prevent any disasters that might occur as a result of Odin's wipe. His unique abilities and loyalty to Asgard would make him a strong candidate for the main character.
One likely antagonist could be those who oppose Naruto having the power of Obelisk the Tormentor. They might see it as a threat to their own power or plans. Maybe some of the rogue ninja groups or even some of the hidden villages that have their own agendas.
Well, it could be that Naruto somehow discovers the power of Obelisk the Tormentor. Maybe he stumbles upon an ancient relic or meets a mysterious figure who bestows this power upon him. Then he has to learn to control it, which might be really difficult as Obelisk the Tormentor's power is extremely potent.
It depends. Sometimes it might be possible, but it often depends on the specific rules and mechanics of the story or the game where the obelisk is involved.
The story of Odin is ancient. It emerged in Norse culture a long time ago and has been shared and adapted for ages. We can't put an exact number on its age, but it's been around for a significant period.
Odin's fate varies in comics. Sometimes he meets his end, but comic universes are known for their fluidity and the possibility of resurrection or alternate timelines. So, the answer depends on which specific comic you're referring to.