@mos_8502 @dhampirdamsel I once ran a long D&D campaign where I had an ancient war between dragons and an ancient divine phoenix. The phoenix was the original source of magic, but after the dragons won the war they replaced the magic with their own.
In the introductory adventure I gave the mage an ancient staff that channeled phoenix magic and it basically turned her into a wild mage until the party figured out what was going on.
That was a fun campaign, I should see if I can revise it for 5e