Each contributes in their own way and style to taking down the opposing forces, with my personal favorite being Gollum whose card calls back to the riddle game in The Hobbit
You gain life, create tokens, and remove all other creatures with an X value over five
The incidental life loss is also a plus
Simply reduce your opponents life total as quickly as possible with all the burn spells, fast creatures, and other red spells in your library
With a little deck manipulation, you can very easily swap one or two mana spells for giant bombs like an Eldrazi creature or even an Omniscience
Fandaniel, Telophoroi Ascian Fandaniel, Telophoroi Ascian is easy to trigger and has a great end step trigger that adds up to a lot of pain for opponents