Here is the full list of all 40 Temple of Endless Night achievements.
Pick Ra as your patron god.
Pick Maat as your patron goddess.
Pick Ptah as your patron god.
Pick Horus as your patron god.
Pick Bastet as your patron goddess.
Pick Sekhmet as your patron goddess.
Pick Hathor as your patron goddess.
Pick Osiris as your patron god.
Pick Seth as your patron god.
Pick Thoth as your patron god.
Play as a scholar.
Play as an alchemist.
Play as a singer.
Play as a priest or a priestess.
Play as a rogue.
Play as a spellsword.
Play as a soldier.
Play as a mercenary.
Realize that one of the workers is missing.
Successfully steal from the caravan.
Learn about the ancient tomb.
Reach the Lost Temple of Amun.
See what lies behind the horizon.
Start a relationship with Zephyros.
Start a relationship with Myrine.
Start a relationship with Apepi.
Start a relationship with Menkaure.
Start a relationship with Persenet.
Enter the Inner Sanctum.
Kill Apepi.
Cleanse the temple in your patron's name.
Help Menkaure retake his throne.
Get possessed by a dark spirit and fail to survive.
Get possessed by a dark spirit and survive.
Stay at the temple and get things back in order.
Leave the temple and never look back.
Destroy the temple.
Lead a successfull rebellion.
Poison your way out of the temple.
Release Apophis.