Here you will be able to find general Glyph priority for the each hero in the game.
Health glyph priority could be always considered as it could change survivability of your hero. When it comes to Armor vs Magic defense glyph, it may depend on server you’re playing in, stats of your hero and what skins do you have. E.g. if the server you’re playing in is heavily focused on Lars and Krista – you might want to level up Magic defense glyph. The same would go if you see a lot of Ishmael or Keira teams – Armor glyph would be a priority.