Notably, Shipwreck Marsh and Underground River account for half of the 16 rares in our deck, so if you already have these cards on Arena , the cost of putting together the deck will be significantly less than its 16-rare price tag would suggest
In this case, you'll put both counters on that creature
Mauhur helps grow this army even larger, and a number of cards synergize with the army including Ugluk (grows when the army or any other creatures die), Gothmog (grants the army deathtouch), Moria Marauder (play spells off the top), Sauron (ring tempts, card draw)
What cards did I miss
I'm trying to make this playable in modern, but it seems to be a little lacking
Holo Foiling and Shine Holographic patterns separate many genuine rare cards from counterfeits