It is extremely impressive and worth the effort
With a Teferi in play, you have the final say in what resolves and what doesnt since your opponents cant respond to your game actions

The Rise of the Floodborn Amethyst and Steel Deck contains: 1x Merlin Shapeshifter (Foil) 1x Tiana Celebrating Princess (Foil) 3x Chip the Teacup 2x Dr Facilier Savvy Opportunist 3x Heihei Persistent Presence 3x Kuzco Wanted Llama 1x Madam Mim Fox 3x Madam Mim Snake 2x Merlin Crab 3x Merlin Goat 1x Merlin Rabbit 2x Merlin Squirrel 2x Freeze (First Chapter) 2x I'm Stuck 2x Beast Forbidding Recluse 2x Benja Guardian of the Dragon Gem 2x Cinderella Knight in Training 2x Eli La Bouff Big Daddy 2x Hercules Hero in Training 1x Kronk Junior Chipmunk 2x Lawrence Jealous Manservant 3x Lilo Galactic Hero (First Chapter) 2x Prince Eric Dashing and Brave (First Chapter) 3x Prince Naveen Penniless Royal 1x The Huntsman Reluctant Enforcer 2x The Prince Never Gives Up 3x Tiana Diligent Waitress 2x Last Cannon 2x Mouse Armor The cards marked as First Chapter are from The First Chapter set, all the others are from the Rise of the Floodborn set

(You cannot halve the same damage twice with this effect.) Damage Eater X DARK Level 2 [ FiendEffect ] ATK 100 DEF 800 During your opponent's turn, when your opponent activates a card or effect that would inflict damage, you can remove from play this card in your Graveyard to change that effect so it increases Life Points by the same amount instead
This Boros phoenix pounds away at opposing life totals on its own before you consider support from cards like Mondrak, Glory Dominus, Purphoros, God of the Forge, or Grateful Apparition
Clive (Special Illustration Rare) Director Clavell of Uva Academy played a vital role in Pokemon Scarlet and Violets Operation Starfall by disguising himself as Clive