Ehren, Lightsworn Monk

Edison Card Text
① If this attacks a Defense Position monster, before Damage Calculation:
Shuffle that monster into the Deck.
② During your End Phase:
Send the top 3 cards of your Deck to the GY.
(Activate & Resolve only if this card is face-up on the field).
No targeting
Damage Step • Substep 3
Banlist • Unlimited
Interactions
Can Krebons activate when attacked by Ehren?✓
Ehren attacks Krebons.
Yes. Krebons can activate at attack declaration, which is earlier than Ehren's Damage Step effect.
If Ehren attacks a set Fulhelmknight, does Fulhelm negate Ehren's ATK?✓
Ehren attacks a face-down Fulhelmknight.
No. Fulhelmknight's effect is at attack declaration, and Ehren's effect applies in the damage step; the set Fulhelmknight is flipped during the damage step and shuffled.
Rulings
edisonformat.net
● If this card attacks a Set monster, that monster is flipped face-up, shuffled into the Deck, and after Damage Calculation its Flip Effect (if any) is activated. However, that Flip Monster’s effect is treated as being activated on the field (and can be negated by Light-Imprisoning Mirror).
● If you control multiple “Lightsworn” monsters, their End Phase effects don’t chain to each other (they each activate, one after another).
edisonformat.com
(1) If this card attacks a Defense Position monster, return that monster to its owner’s Deck before damage calculation. (2) During each of your End Phases, send the top 3 cards of your Deck to the Graveyard.
The (1) mandatory Trigger Effect activates in Substep 3 - Before Damage Calculation.
This effect activates after Set monsters are Flipped face-up (in Substep 2).
A Set Flip Monster's Flip Effect will activate and resolve normally in Substep 6 - Resolve Effects.
A Set "Nightmare Penguin's" effect will still activate if attacked by Ehren [REF1], [REF2].
When this effect is applied, Substep 4 - Damage Calculation does not occur.
This effect will not activate if Ehren leaves the field earlier in the Damage Step.
Ex: "Sasuke Samurai #4's" effect destroys Ehren in Substep 1 - Start of the Damage Step.
The (2) mandatory Trigger Effect must resolve (even if the effect is negated) before the turn can end.
If you do not have enough cards to send to the Graveyard remaining in your Deck when resolving this effect, all cards remaining in your Deck are sent to the Graveyard.
If the activation of this effect is negated by "Light and Darkness Dragon," it will activate again in the same End Phase [REF]].
If this effect is negated by "Skill Drain," it will not activate again in the same End Phase [REF]].
The "Lightsworn" monster (or "Judgment Dragon") must remain face-up on the field in order to activate and resolve this effect.
If your opponent activates "Book of Eclipse" after you resolve this effect, when "Book of Eclipse" resolves and your affected monsters are flipped face-up (and you draw 1 card for each) then each "Lightsworn" monster (or "Judgment Dragon") will once again activate this effect [REF]]
(2) VS. "Brain Control": Player A gains control of Player B's "Lightsworn" monster until the End Phase. During the End Phase, Player A may decide in which order to activate/resolve effects:
Player A resolves "Brain Control" first, restoring control of the "Lightsworn" monster to Player B. That "Lightsworn" monster is no longer controlled by the turn player, thus its effect will not activate.
Player A activates and resolves the "Lightsworn" monster's effect to send cards from the top of their Deck to the Graveyard. Then that "Lightsworn" monster is returned to Player B's control [REF]].
(2) VS. "Enemy Controller":
During Player A's turn, Player B gains control of Player A's "Lightsworn" monster. During the End Phase, when control of the "Lightsworn" monster is restored to Player A, its mandatory Trigger Effect will activate [REF]].