Once this is in play, do I put cards into the cemetery that I own or the cemetery that I control?
You always put your cards into the cemetery you own (the one nearby your deck).
If I have Wormelow Tump in play, what happens?
The cemeteries are still swapped, and you protect everything in 'your' cemetery (which is really your opponent's).
If there are an even number of Mismanaged Mortuaries in play, do they cancel out?
Yes.
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