Millennium Revelation — Ruling

Effetto 1

This card's effect that adds Monster Reborn from your Deck or Graveyard to your hand is an effect that activates on the field. (It does not target. It can be activated optionally during your Main Phase. Sending 1 Divine-Beast monster from your hand to the Graveyard is the cost to activate this effect.)

This card's effect that allows you to Special Summon The Winged Dragon of Ra with the effect of Monster Reborn is an effect that activates on the field. (It does not target. It can be activated optionally during your Main Phase. Sending this face-up card in your Spell & Trap Zone to the Graveyard is the cost to activate this effect.)
Sending The Winged Dragon of Ra that was Special Summoned by the effect of Monster Reborn to the Graveyard during the End Phase does not start a Chain.