FlowerSunRain
Contributor
(Related, but not exactly the same)
Electropotence
Rivalry
Magus of the Scroll
Arc Blade
There's one in almost every block. Sometimes its an enchantment, sometimes its a creature, but they all let you do damage whenever you do something. I like these cards. They give red decks reach, but they do it in an interesting way, unlike, say, fireblast. Because these cards are based on what you do, you can build around them. Most can hit creatures, so they double as removal. They create interactive game states. Some of them are too limited too be used as written in a cube (looking at you burning vengeance!), but most of them do there job well.
In fact, in Purphoros's case, a little too well if you ask me, I really don't like him as written. He does cost more then the others, but with no activation cost, an easy trigger condition that doesn't cost resources, indestructibility, a random activated ability and sometimes being a HUGE CREATURE, he's a little over the line in my view.
So, did I miss any important ones? Which do/would you use? Is there an easy bandaid to make Purphoros non-miserable, because I love the idea of the card (not the execution). How many of these cards just pulls you into too many directions?