This would be a cool name for a mono ghost team, but idk honestly. Short and sweet I think Garchomp is a better dragon wall for this team because of it's speed. dregion and chomp are very similar but it is your choice. I suggest the classic stealth rocks build if you are going to replace stealth rocks on ferrothorn for gyro ball.Use stealth rocks build with swords dance.
Also, destiny bond is VERY DIFFICULT to master on a scarfed gengar so watch out for that, I would suggest replacing it with HP ice for more coverage.
Overall I love your team, GL. :D