Can I target a Karmic Guide in my graveyard with an Animate Dead?
The results are... interesting.
Karmic Guide’s protection from black ability only functions while it’s on the battlefield, and so Animate Dead can legally enchant it when it’s just a card in its owner’s graveyard.
When Animate Dead’s ETB trigger resolves, it will return Karmic Guide to the battlefield but then be unable to attach itself to Karmic Guide on the battlefield. This means that Animate Dead isn’t enchanting anything. When state-based actions are checked, Animate Dead will be put into its owner’s graveyard because it’s an unattached Aura on the battlefield. Finally, before anyone gets priority, both Karmic Guide’s ETB trigger and Animate Dead’s LTB trigger go on the stack.
Once everything is said and done, both Karmic Guide and Animate Dead are in their owners’ graveyards and another creature from Animate Dead’s controller’s graveyard has been returned to the battlefield.