That seems to be just for flavor, and summon doesn't have any impact on the rules that we know of
That way, it will have the same weight and feel as an actual card
We're excluding multicolor cards as well as cards with other colored mana symbols in their text box like Chatterfang, Squirrel General, so any Commander deck with green can use any of these cards
You dont really need any particular synergy for this to be worth slotting, but its a great way to fill your graveyard or pump sizing-sensitive cards like Alesha, Who Laughs at Fate
In each category, I'll give an unordered top 5 list for anti-Infect cards, one honorable mention that is "good enough", and one "trap" card that seems good but is actually terrible
It can even remove indestructible creatures, turn off any abilities that activate when a creature dies, and/or keep your best creature about