A true immortal level fiend tool would be called a true fiend tool.
A heaven immortal grade demonic equipment would be called a heaven demonic equipment.
Gold immortal grade fiend artifacts were called fiend soul artifacts.
After the heavenly demonic Pagoda became a top-grade demonic soul tool, The Fiend King placed it on the demon planet. He had the pagoda suppress the planet while letting the demons in the pagoda come out to guard all the immortals.
Even though these sky demons were weak, they didn't have a body. They were invisible and specialized in dealing with primordial spirits. They wouldn't be blocked by world realm formations because the sky demon Pagoda itself was created by borrowing the power of the heavenly Dao and was born from fate energy.
In the 1800th year of the eight barren era, the Empyrean demon tribulation began in secret.
