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For six mana, Muldrotha does quite a bit where during each of your turns, you may play a land card and cast a permanent spell of each permanent type from your graveyard meaning you can really leverage your graveyard to accumulate a ton of value during games, perhaps with an Overlord of the Balemurk on the battlefield for good measure
Players can't take actions in between the time you destroy the target creature and the time it returns to the battlefield under your control
If you use pages and have the ability to spend the money, you should definitely get these
In white you have cards like Angelic Accord, in black there are cards like Sanguine Bond, and in blue Marina Vendrell's Grimoire
Reading MaRos comments over the weekend, I still agree with him that the playtest cards are problematic