It turned the downside of Hellbent aggressive strategies into a massive upside
Some split cards such as Who // What // When // Where // Why are part of the un-sets, and so aren't legal to play in most formats
Getting free value for doing what you are already doing is great
I dont have the room to go down every single one of them, but here are a few of the most common ones plus some of my own personal fun favorites for when I need to name a random type (like when I cast Gathering Stone): Avatar Beeble Cleric Dog Elf Faerie Goblin Hero Human Hydra Merfolk Ninja Otter Phoenix Rogue Sponge Toy Wizard Zombie Land Subtypes There are five basic land subtypes that you probably know pretty well: Plains, Island, Swamp, Mountain, and Forest
Its full of ample value if you do and recurring a [casthaven]Sundering Growth[/casthaven], [casthaven]Wayward Temple[/casthaven] and a fetchland feels pretty good
Some Magic: The Gathering cards are just a little too good, particularly in more specialized formats