"Joan's attached cards cannot affect opposing dudes unless they have bounty higher than their influence."
Affecting opposing Dudes. See compendium for examples on Yagn's meaning you can't boot for Jael's Guile and the entries on Bio-Charged neutralizer for examples.
Jael's Guile will only affect certain dudes.
Scoop Hound affects shootout plays, not dudes, so it does not interact with Joan (reversal)
Casualties aren't direct from one dude to another, it creates a "pool" of casualties and then they need to be soaked up. Joan would NOT keep an attached Eleanor from causing a casualty against a specific dude.
If Joan has a Mayfair Family Deck that would allow her to cast Malison, she can cast it because it doesn't affect opposing dudes.
Heartseeker: Reduce your opponent's casualties by three this round. If you win this round, ace the opposing shooter. This acing effect cannot be prevented (even if the shooter is Harrowed).
If Joan has a Mayfair Family Deck and casts Heartseeker, it can be cast and the opposing shooter will be aced.
The thread will remain unlocked for follow up. Malison and Scoop Hound ruling has been updated.