The rest should, hopefully, come off the top of your deck as you draw cards
for a broader audience
Brotherhood Outcast isnt bad, but competes with far stronger cards in this archetype already
Set completionists hunting full master sets including secret rares
Alchemy is a reasonable analogue to Mystical Teachings, but only because it interacts with sorceries, creatures, planeswalkers, enchantments, artifacts, and lands
Soul Crossing is the one Egyptian God support card that's generally useful, assuming the opponent has three monsters on their board to Tribute, but it has the unique handicap of allowing only one non-Divine-Beast effect for the rest of the turn and the next