A Ritual Monster must first be "properly" summoned via its Ritual method. If it is sent to the Graveyard without being Ritual Summoned first (e.g., via Foolish Burial), it cannot be revived by cards like Monster Reborn . Historical Eras of Ritual Summoning
Ritual mechanics have evolved through three distinct phases: Okay Yu-Gi-Oh, Can We Talk About Ritual Monsters? Ritual Summon.rar
To perform a standard Ritual Summon, you typically need three components: A Ritual Monster must first be "properly" summoned
Monsters from your hand or field whose total Levels equal or exceed the Level of the Ritual Monster. via Foolish Burial)