In the case of Great Wall, this includes all four creatures in Magic that naturally have plainswalk the menaces known as Boggart Arsonists, Graceful Antelope, Righteous Avengers, and Zodiac Rooster
This rare red card is still plenty cheap, but it has doubled in value since the latest set, Aetherdrift, came out, and still seems to be climbing
The Necrobloom is a perfect support piece since dredge lets you easily bring the lands that you sacrifice and mill back
The partners looked fun to build around and I already had a list of fun cards to include, like Wound Reflection / Archfiend of Despair to 1-shot people with Virtus, or draw all the cards with Gorm equipped with Infiltration Lens
Multiplayer games like Commander are less matchup dependant, and you can get away with any of these in your deck, but probably not all of them