It ensures your deck is well-rounded and functional, containing not just the fun, thematic cards that execute your strategy, but also the essential ramp, draw, and interaction needed to survive a multiplayer game
Surprisingly, decks built around Reyav can often outperform those built around Mirror-Shield Hoplite
Getting double of something is always better than one of something if youre the one actively doing it
The tokens you generate wont have heroic
However, Commander games can be pretty long and require a lot of planning to arrange and then a lot of effort to play, so cards destroy all lands in play like Armageddon, Devastation, and Ravages of War can be extremely frustrating to play against if no one can counter them
Whenever an opponent scries, surveils, or searches their library, River Song gets a +1/+1 counter and then deals damage to that player equal to its power