mtg ikoria commander deck 2020 (Ikoria) Ikoria Lair of Behemoths -

It makes artifacts on entering, gives you a way to sacrifice them, and gives you access to the four colours that most care about artifacts

You can cleave it as an alternate cost, and then you net a free spell for the turn, and I love it on an enemy's turn when you cast this for free, to bounce what your foe played and then drop a flash thing like Hullbreaker Horror or Ancient Stone Idol or you can just cast another instant that draws you cards

For Riders of Rohan, this might involve leveraging the Monarch mechanic to draw extra cards and deploying Human tokens to build a formidable army

These are the only Iconic cards in the set and have a unique foiling treatment

Six of them are pure white, seven are green