The creature comes back onto the battlefield as a new creature, with one +1/+1 counter on it (plus any other counters that it would normally enter with).

If Otherworldly Journey is cast during an end step, the creature won't return until the beginning of the next end step.

Any Aura attached to the creature is put into its owner's graveyard as a state-based action. Equipment attached to the creature become unattached but remain on the battlefield.