Drowner of Hope

• WWizards of the Coast2015-08-25
  Official Ruling
  You can't sacrifice the same permanent to pay two different costs. Notably, if you sacrifice an Eldrazi Scion to activate the last ability of Drowner of Hope, you won't add .
• WWizards of the Coast2015-08-25
  Official Ruling
  You can sacrifice any Eldrazi Scion to activate Drowner of Hope's last ability, not just one created by Drowner of Hope.
• WWizards of the Coast2015-08-25
  Official Ruling
  A card with devoid is just colorless. It's not colorless and the colors of mana in its mana cost.
• WWizards of the Coast2015-08-25
  Official Ruling
  If a card loses devoid, it will still be colorless. This is because effects that change an object's color (like the one created by devoid) are considered before the object loses devoid.
• WWizards of the Coast2015-08-25
  Official Ruling
  Eldrazi Scions are similar to Eldrazi Spawn, seen in the Zendikar block. Note that Eldrazi Scions are 1/1, not 0/1.
• WWizards of the Coast2015-08-25
  Official Ruling
  Other cards and abilities can give a card with devoid color. If that happens, it's just the new color, not that color and colorless.
• WWizards of the Coast2015-08-25
  Official Ruling
  Eldrazi and Scion are each separate creature types. Anything that affects Eldrazi will affect these tokens, for example.
• WWizards of the Coast2015-08-25
  Official Ruling
  Cards with devoid use frames that are variations of the transparent frame traditionally used for Eldrazi. The top part of the card features some color over a background based on the texture of the hedrons that once imprisoned the Eldrazi. This coloration is intended to aid deckbuilding and game play.
• WWizards of the Coast2015-08-25
  Official Ruling
  Sacrificing an Eldrazi Scion creature token to add is a mana ability. It doesn't use the stack and can't be responded to.
• WWizards of the Coast2015-08-25
  Official Ruling
  Devoid works in all zones, not just on the battlefield.
• WWizards of the Coast2015-08-25
  Official Ruling
  Some instants and sorceries that create Eldrazi Scions require targets. If all targets for such a spell have become illegal by the time that spell tries to resolve, the spell won't resolve and none of its effects will happen. You won't get any Eldrazi Scions.

Rulings via Scryfall