Edison format ruling
Chaos Emperor Dragon - Envoy of the End

Card effect (current official text)Cannot be Normal Summoned/Set. Must be Special Summoned (from your hand) by banishing 1 LIGHT and 1 DARK monster from your GY. Once per turn: You can pay 1000 LP; send as many cards in both players' hands and on the field as possible to the GY, then inflict 300 damage to your opponent for each card sent to the opponent's GY by this effect. You cannot activate other cards or effects during the turn you activate this card's effect.
Rulings
- Chaos Emperor Dragon - Envoy of the End sends itself to the GY as part of its effect, and counts itself for determining how much damage it inflicts.
- The damage that Chaos Emperor Dragon - Envoy of the End inflicts is equal to the number of cards BOTH players send to the GY times 300 points.
- Barrel Behind the Door and Trap of Board Eraser can be chained to Chaos Emperor Dragon - Envoy of the End's effect. Barrel Behind the Door is, itself, sent to the GY by Chaos Emperor Dragon - Envoy of the End's effect and counts for an additional 300 points as a result.
- If Chaos Emperor Dragon - Envoy of the End is destroyed or removed from play by an effect chained to its own effect, its effect still resolves.
- Tokens will be removed from the field by Chaos Emperor Dragon - Envoy of the End's effect, but will not add to the damage total because they are not sent to the GY.
- It is the controller, not the owner, of Chaos Emperor Dragon - Envoy of the End that can activate its effect and that inflicts damage to his/her opponent.
- If Chaos Emperor Dragon - Envoy of the End is Special Summoned, and the controller immediately activates its effect, and the opponent chains Torrential Tribute as Step 2 of a chain, Torrential Tribute destroys all monsters on the field and sends them to the GY, then Chaos Emperor Dragon - Envoy of the End's effect resolves, sends all Spell & Trap Cards on the field to the GY, and inflicts 300 points of damage to the opponent for each Spell & Trap Card sent to the GY by its effect. (Monster Cards do not count toward the damage because they were destroyed and sent to the GY in the middle of the chain by Torrential Tribute.)
- If Waboku is chained to the effect of Chaos Emperor Dragon - Envoy of the End, it will not prevent the damage because Waboku only applies to Battle Damage. Also, Waboku will still be on the field when Chaos Emperor Dragon - Envoy of the End's effect is applied, so it will still count for 300 points of damage to the opponent.
- When Minar and Electric Snake are sent to the GY by Chaos Emperor Dragon - Envoy of the End, their effects are not activated because the modified text on those cards says when they are discarded to the GY from the hand.
Rulings data courtesy of Format Library — formatlibrary.com. Spotted an inaccuracy? Flag it in the Edison forum — sourced change requests get reviewed.