Youre not casting a spell but activating an ability, Amphin Mutineer is not entering from the graveyard so neither of these cards will stop you
Only one creature may be sacrificed as an additional cost for paying casualty
there have also been decks for Magics Commander format (more on that later) for Warhammer 40,000, and upcoming products include Doctor Who, Final Fantasy, and more
In order to play a card or an ability, you must sacrifice a land that produces at least one colored mana of the card you're playing
The EA nonfoil slot is pretty easy, since youre 97% to get a rare and 3% to get the one EA mythic rare
Valgavoth, Terror Eater feasts on sacrificed permanents and is a great reanimator target that just takes over games