mtg meta commander decks Magic: the Gathering etched Display Commander (a thick cardstock copy of the commander card with foil etched into the cards border and art) Wizards of The Coast Magic:

Even if you gain control of your opponents Artifacts, reaching the 20 Artifact requirement should still be very hard

They may do something else with their turn besides kill Nissa, thinking they have another turn until shes actually a threat, but Ulvenwald Hydra typically throws a wrench into their plans

Scrawling Crawler Rarity: Rare TYPE: Artifact Creature SUBTYPE: Phyrexian Construct CMC: 3 Mana cost: USD: $7.06 EUR: 6.82 TIX: 0.03 EDHREC RANK: 648 (3/2) At the beginning of your upkeep, each player draws a card

Copying artifacts and enchantments can get out of hand, though this is all fiddly enough that I wouldnt expect it to be too problematic

Graded Population Report: Wakka, Devoted Guardian [Foil] #97 Visualize the distrbution of grades in the chart