Honorable Mention: The Crystals I think that these cards are going to be very fun in casual EDH
Depending on how popular this Commander is, that could lead to a fairly large amount of consistent demand
From here, you can copy Vivis ability again, which bypasses the once-per-turn clause on Vivi
You can activate Arcum for Sewer Cam, untap him, Arcum for Repurposing Bay, sac the Cam to get Corridor Monitor, untap Arcum and hold priority to sac the Monitor for Encroaching Mycosynth, and now you can even sac Arcum to himself to get Mind Over Matter, and use Repurposing Bay to get The One Ring, and now you can fire off the MoM + TOR combo you mention
Provided you can get through the queue, which often breaks in drops like this, if you're not there the second sales open, you'll likely be too late to grab them