I know a lot of people wanted Dream Devourer as a commander, and well there he is as Edgin, u/Yojimbra commented on Reddit
6 Rite Of Harmony Rite of Harmony is best used in green-white Elf decks, since the Elf tribe sometimes uses hybrid green-white cards from the Shadowmoor and Eventide sets
There are also cards like Overlord of the Hauntwoods which creates mana-producing lands from thin air, Defiler of Vigor which lets you pay life instead of green mana, and Domri, Anarch of Bolas which both adds mana and prevents your creatures from being countered
Having first strike is going to make him annoying to block, especially when you can start to stack the +1/+1 counters onto him
In any case, it should be obvious that these decks are competing with each other for metagame sharealthough I do consider Lightning Bolt and Nahiri, the Harbinger two pretty strong arguments for the superiority of Jeskai
This means were unlikely to see a new card that does something similar, and certainly not one that does so on the same level