If I cast a Magic as a Spirit minion, will Orb of Ba'al Berith copy it?
Good try, but no. You're casting it as a minion, so the game sees it as a Minion spell, not a Magic spell.
If I increase or decrease the cost of a magic while I cast it as a Spirit minion, how much power will it have in the realm?
Use the printed cost of the magic as its power, regardless of how much mana you actually spent to cast it. Note that magics with X as their cost work appropriately, based on the unmodified cost of the spell when you cast it.
If I cast a magic with X as its cost (e.g. Arcane Barrage) as a Spirit minion, will the minion retain the correct power?
Yes, because of the golden rule. If you pay 7 mana for your Arcane Barrage Spirit minion, it will have 7 power while in the realm.
If Selfsame Simulacrum is summoned as a basic copy of an animated magic, what happens?
'Basic copy' refers to the printed characteristics of the card, which means Selfsame will try to become a magic. But magics cannot exist in the realm, so Selfsame Simulacrum would immediately go to the cemetery and there would be no effect of the magic. Sorry!
If I cast a magic as a Spirit minion, do I still get the effect of the magic?
No. Treat the textbox of the magic as entirely blank, though it retains its elements and rarity. For example, if you cast Craterize as Spirit minion, you do not need to discard a site as an additional cost, and it will be summoned as an 8 power, Elite earth minion.
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