Majesty or Vanity's Fiend?

[Butter]

Both have their advantages and disadvantages.
Majesty
Pros:
Synergizes with Monarch support
Stops effects outright
Cons:
Opponent can still pendulum summon

Vanity
Pros:
Stops special summons outright.
Less likely to be stopped with protection
Cons: Effects can still be used to remove it
Makes bricky hands more unplayable because it doesn't have the stats of a monarch

Which is better to use this format?

[SynjoDeonecros]

Well, it all depends on which deck you're putting them in, but overall... I say either/or, honestly. I'm leaning more toward Majesty's Fiend, simply because I have 2 copies of them and no copies of Vanity's, but it's ultimately up to you.