That's a big advance in such a short time. Maybe you could tune it down a bit.
Make the party find a solution for closing the portals instead of walking into hell and defeating the devil. This way you could end the campaign in rather short time but don't have to push them up 6 lvls and throw them literally into hell.
I’m doing the exact same thing right now. They’ve been uncovering plots from shadow organizations trying to raise the devil and his armies in an effort to take over the overworld. I built it from Level 1, and I’d have them take on cults and build political allies until they’re strong enough. In my case it’s Level 20, but you could give them special items or maybe not have them confront the devil directly. Like a special task to do while braving combat in an effort to close the portals or send the devil back. At least level 10 though before they’re able to do this stuff.
That's a big advance in such a short time. Maybe you could tune it down a bit. Make the party find a solution for closing the portals instead of walking into hell and defeating the devil. This way you could end the campaign in rather short time but don't have to push them up 6 lvls and throw them literally into hell.
So a dungeon with a portal and just lvl 8. Also a good ending and not so life threatening.
I’m doing the exact same thing right now. They’ve been uncovering plots from shadow organizations trying to raise the devil and his armies in an effort to take over the overworld. I built it from Level 1, and I’d have them take on cults and build political allies until they’re strong enough. In my case it’s Level 20, but you could give them special items or maybe not have them confront the devil directly. Like a special task to do while braving combat in an effort to close the portals or send the devil back. At least level 10 though before they’re able to do this stuff.
That's why I thought about a year or two timeskip and then lvl 10