If you like defying Heaven as a plot, read "My Simulated Path to Immortality", in the story, cultivators found a way for everyone to become a cultivator regardless of spiritual roots, which went against Heaven and to limit the number of cultivators, it made it so for every person that cultivates...
The Dao Paths and the Heavenly Dao are not mutually exclusive, although i do wonder why those 2 things are both called "Dao" when one is basically just paths/expertise while the other is a semi-living subconscious will of the universe, basically God, what do they have in common?
Its a simple agreement, they contribute to the war effort with barely any effort in exchange for being duty-bound to not abuse that cushy position and actually protect the Pass 24/7
Its immersion breaking seeing self centered characters speak and even cry of higher purpose like sacrifice for mankind or nation, but i've seen it way too often in chinese stories
How do i say it...................... so i saw rule 34 of Martial Peak quite a while back.......
including of characters i haven't seen at the time, and this little girl is one of them, although this is clearly not her real form
Ye only Open Heaven can enter the battlefield but there should be quite a few people born IN the actual battlefield, after all they have entire cities there and people who live there for thousands of years unable to leave