Ghost Rider's role in the story primarily takes place in the Dark Kingdom and is heavily focused on taking down Jedah, alongside Dante. Sometimes in 88 days ago after the convergence, Ghost Rider and Dante met each other while doing their similar evil demon hunting business, prior Dante being called to aid their fellow heroes against Ultron Sigma.
When the battle against Ultron Sigma occurs 88 days later, Ghost Rider sensed over one million souls being sacrificed and gathered inside the Dark Kingdom, and began tracking the one who responsible for this cause. He comes across Morrigan, who tries to tempt Ghost Rider to fall for her charms and even tries to make him do the Penance Stare on her. Ghost Rider, however, replies that she may have many sins of stealing some souls, but is not responsible on this recent soul stealing causes, while resisting her charms. Morrigan, however, isn't too pleased with this and fights Ghost Rider to in order to get him seduced, much to Ghost Rider's chargin.
Doctor Strange, Dante and Arthur then arrives and puts a stop to their fight while revealing the need to find the Soul Stone. Morrigan then leads them to Jedah, who has the Soul Stone and is also the one Ghost Rider is looking for. After the defeat of Dormammu and Firebrand, Jedah retreats while still in possession of Soul Stone. Ghost Rider and Morrigan joins the other heroes to try and take down Jedah, and later Ultron Sigma.
Gorrigan is a rare pair. The ship is mainly based on the fact that Morrigan attempted to seduce Ghost Rider (Johnny Blaze) inside the Dark Kingdom, where they put their differences aside, after which she aided him in his quest to find Jedah. The fact that she joined Ghost Rider and the other heroes to try and take down Jedah, and later Ultron Sigma also showed signs that she had a heart which many fans liked.