Dragons of Tarkir did them as two-color cards for each ally-color pair
Some might refer to them as Insufferable Braggers, but thats neither here nor there
Furthermore, it can also destroy cards equal to the number of co-linked monsters on the field, making it great for breaking boards when going second after the player establishes the start of their combo
Until end of turn, this creature gains indestructible and gets +1/+1 for each card type among cards in your graveyard
For example, if the target historic permanent card is an artifact card (but not a creature card) and you control March of the Machines ("Each noncreature artifact is an artifact creature with power and toughness each equal to its mana value."), it will enter with two additional +1/+1 counters on it because it will be a creature on the battlefield
Several factors influence Obsidian Flames card values: card condition (mint cards worth 3-5x more), rarity (holographic and rare cards command higher prices), first edition status, PSA/BGS grading scores, and market demand for specific Pokemon