It turns cards like Merfolk SecretkeeperMerfolk Secretkeeper and Fractured SanityFractured Sanity into nukes of a mill spell, and allows Altar of the BroodAltar of the Brood, Ruin CrabRuin Crab and Hedron CrabHedron Crab to be absolute menaces
That's pretty heavily played, but...why
Mushu - Majestic Dragon is a protective Ruby and Steel card
STRIXHAVEN Fervent Mastery Fervent Mastery is an interesting one, and Ive yet to play with it myself, but it has me scratching my head about whether I should be building around it more to take advantage of its unparalleled ability to see the cards you want
Treacherer is the old web application, still available on this site
Also, if you happen to be in the Seattle or Portland areas, you could just go into the shop and pick it up directly