Darkness is the Fog equivalent for black, and Holy Day is the Fog analog for white
Archmage Emeritus triggers a draw for every instant or sorcery you cast or copy, which is essential for sustaining the high-mana requirements of the Opus mechanic
This combo, which is easy to assemble with Scavenger's Talent, used to be fruitless in the face of Vein Ripper, as your opponent would drain you twice as fast
[Darkness][Colorless][Colorless] Tighten Up 60 Your opponent discards 2 cards from their hand
I am not trying to discourage you from playing the deck, I think it is a solid choice, but be aware that a normal Lost Box deck (like the one we covered above with Zamazenta) can be less risky
So for Seventh Tachyon, collectors rare is the highest rarity you will find in its original set