Crown of Flames is an Enchantment originally printed in Tempest, and later reprinted in Invasion. This one-drop Aura has two abilities, each of which costs one Red mana. One gives the Enchanted creature “firebreathing” or +1/+0 until end of turn. You can activate this ability as many times as you have mana to pay for it. The second ability allows you to pay one Red mana to return Crown of Flames to its owner’s hand. This means if the creature is going to be destroyed or otherwise removed from the field, you can save this Aura in order to use it later.
For a common Aura, especially one that was printed so many years ago, Crown of Flames is a decent card. But does it still see any play anywhere? Actually, some Anax and Cymede EDH decks play a copy. This is mostly because Anax and Cymede decks play a lot of Heroic creatures. Because Auras target the creature they are Enchanting, they trigger Heroic abilities. So, it’s a pretty efficient card in that deck, since you can get it back to your hand and then target another creature.
Some Valduk, Keeper of the Flames decks have been seen to play Crown of Flames, too. As Valduk is happy to have as many Auras and Equipments placed on him as possible in order to create more Elemental creature tokens, this card is a cheap option. It’s far from the best card for Valduk, but for a one-mana Aura, it’s certainly not the worst choice.
Have you ever played with Crown of Flames? It’s a decent little common, even if its play-ability today is fairly limited to a few EDH decks.