For an Immortal King powerhouse, obtaining an Emperor-grade cultivation method is extremely difficult, but getting a King-grade cultivation method is quite simple.
For an Immortal Emperor powerhouse, getting a Divine-grade cultivation method is very difficult, but acquiring an Emperor-grade cultivation method is not hard at all.
Precisely because of this, almost no one breaks through to achieve cultivation realms above the "Immortal King" using only Heavenly-grade cultivation methods; at most, they manage to break through to become an "Immortal Monarch."
Chapter 2808