You can only use this effect of "Eva" once per turn
If a Continuous Spell or Trap copied by this card would have an effect that requires you to activate the card in question (Call of the Haunted, Fiendish Chain, Fire Formation Tenki, etc) then this card doesn't really do anything because it just becomes the effect, and doesn't re-do the activation part of it
If that wasnt enough stopping power for your liking, you can also detach an XYZ material to negate the effect of every single monster your opponent controls (providing they have attack less than Mermail Abyssgaios)
That being said, what's actually popping off from the new set
This is why there has been a ban list for the official tournament scene for almost the entire existence of the competitive formats
With Eldlich in the deck, you will have another win condition thanks to Eldlich the Golden Lord's strong recursion effect and high ATK stats