Just did various tests on Thran Vigil. It triggers twice when a creature/artifact enters the battlefield from a graveyard, but triggers only once when a creature/artifact leaves the graveyard to a different zone. Tested this with self-reanimating creatures (Tizerus Charger), self-reanimating artifacts (Sword of the Meek), both (Scrapwork Rager), and reanimation spells (Unbreakable Bond), all resulting in double triggers. Tested this with exile (Jack-O-Lantern), raise dead effects (Codex Shredder), and shuffle effects (Perpetual Timepiece), all resulting in single triggers.