“a non-believer and arrogant millennial guy ” = protagonist
“performs a ritual and loses his body” = inciting incident
he must … “get his body back before it gets cremated” = main character goal

If this were my logline, I’d ask why an arrogant, non-believer was reading centuries old Indian rituals in the first place? While fiction is, well … not reality, it does model itself on the stuff of life, making plausibility an important criteria to consider. Most storytelling does well when it introduces a likable, albeit fundamentally flawed character. Arrogance is our hero’s flaw, but what might be their positive traits, their skill or something special?

If arrogance is his flaw, then the character arc might be to transform into a selfless person. In what way might the story conflict facilitate this transformation? While, yes, he wants his body back (still all about his needs, and affirming his arrogance), what magic puzzle, troll at the gate, secret password must he solve to win it back? Think maybe Dorothy, who in order to get back home (to get back something she lost), she must kill the Wicked Witch, and get her broom back to the Wizard …