Abilities and effects which care about attackers and blockers which have left the battlefield need to be streamlined

[theelk801]

Example: BlockedByIdPredicate and BlockingAttackerIdPredicate are used in card constructors with the card's UUID, which doesn't work if an ability is copied elsewhere.

Example: [[Kardur, Doomscourge]] uses a special triggered ability when there should ideally be a filter/predicate that can match dead attackers

My implementation of [[Baneclaw Marauder]] in #8200 can hopefully be generalized for this.

[github-actions[bot]]

Kardur, Doomscourge - (Gatherer) (Scryfall) (EDHREC)

{2}{B}{R} Legendary Creature — Demon Berserker 4/3 When Kardur, Doomscourge enters the battlefield, until your next turn, creatures your opponents control attack each combat if able and attack a player other than you if able. Whenever an attacking creature dies, each opponent loses 1 life and you gain 1 life.

Baneblade Scoundrel // Baneclaw Marauder - (Gatherer) (Scryfall) (EDHREC)

{3}{B} Creature — Human Rogue Werewolf 4/3 Whenever Baneblade Scoundrel becomes blocked, each creature blocking it gets -1/-1 until end of turn. Daybound (If a player casts no spells during their own turn, it becomes night next turn.) :arrows_counterclockwise: Creature — Werewolf 5/4 Whenever Baneclaw Marauder becomes blocked, each creature blocking it gets -1/-1 until end of turn. Whenever a creature blocking Baneclaw Marauder dies, that creature's controller loses 1 life. Nightbound (If a player casts at least two spells during their own turn, it becomes day next turn.)

[awjackson]

Related issue: https://github.com/magefree/mage/issues/9493 Information about which player or planeswalker a creature is attacking, or which creature(s) it's blocking, are only stored in the Combat class, and there's currently no way to retrieve that information for permanents that have left the battlefield short of using some kind of watcher.

This also affects all targetted abilities that use a target with DefendingPlayerControlsPredicate.

[weirddan455]

I made some improvements to attacking creatures dying including getting rid of that special triggered ability Kardur Doomscourge was using in PR #9480

I think for #9493 there's a much simpler solution. See my comment there.