The White Stone of Legend

(1) When this card is sent to the GY, add 1 Blue-Eyes White Dragon from your Deck to your hand.

• This (1) mandatory Trigger Effect activates &  resolves in the GY.
• This effect will activate even if no copies of Blue-Eyes White Dragon remain in your Deck. In this case: your opponent can briefly check your Deck to verify, unless all 3 copies of Blue-Eyes White Dragon can be accounted for in the GY / field / removed from play (face-up).
• This effect will activate even when The White Stone of Legend was discarded for hand size. In this case: discarding for hand size is the very last action in the End Phase. Only mandatory effects and Counter Trap Cards can be activated beyond this point.
• Example: It is Player A's End Phase and they have a Set Divine Wrath from a  previous turn. Player A discards two copies of The White Stone of Legend to bring their hand size down to 6 cards. However, The White Stone of Legend has a mandatory Trigger Effect to add a Blue-Eyes White Dragon from the Deck to the hand, and Player B controls a Doomcaliber Knight. Thus, a chain is built with both The White Stone of Legend's effects forming a chain as Chain Links 1 and 2, and Doomcaliber Knight Tributing itself as Chain Link 3. Player A activates Divine Wrath as Chain Link 4 and discards a card as cost. When resolving the chain, Divine Wrath will successfully negate the effect of Doomcaliber Knight, then both effects of The White Stone of Legend will add a copy of Blue-Eyes White Dragon to Player A's hand (should any remain in the Deck). Once the chain has resolved, no chains may be built (unless mandatory Trigger/Trigger-like Effects were activated) and Player A must once again discard down to their hand limit and the turn ends.