"the undead menace is vanquished from Reikland!"
I'm no scholar, but is that correct?
Vanquished is past tense, utterly destroyed.
'he is destroyed from your house'?
Maybe exorcised?
And
Vanquished is past tense. Is is present tense.
"the undead menace was vanquished from Reikland!"
Better, but they are still being destroyed from a place, which makes no sense to me.
"the undead menace was exorcised from Reikland!"
Sounds better to me.