If your opponent can kill it, the Enchantment will still generate tons of value
With Scarlet & Violet series now underway, it's interesting to go back and look at some of the most expensive cards from previous eras

NTC Gadget Vampire Midrange # Main Deck 1 Black Luster Soldier - Envoy of the Beginning 2 Blade Knight 1 Book of Moon 2 Bottomless Trap Hole 1 Breaker the Magical Warrior 2 Dekoichi the Battlechanted Locomotive 1 Don Zaloog 1 Elemental HERO Wildheart 2 Gaia Power 2 Giant Rat 2 Green Gadget 1 Heavy Storm 2 Kycoo the Ghost Destroyer 1 Limiter Removal 1 Mirage Dragon 1 Mirror Force 1 Mobius the Frost Monarch 1 Pot of Greed 1 Premature Burial 1 Pyramid Turtle 2 Red Gadget 1 Ring of Destruction 2 Sakuretsu Armor 2 Shrink 2 Smashing Ground 1 Solemn Judgment 2 Ultimate Offering 2 Vampire Lord 2 Yellow Gadget 2 Zaborg the Thunder Monarch # Extra Deck None # Side Deck 1 Enemy Controller 2 Mind Control 2 Mirage Dragon 3 Royal Decree 3 Seven Tools of the Bandit 1 Shield Crush 1 Solemn Scolding 1 Soul Exchange 1 Trap Hole Claudio Earth Zombie Beatdown # Main Deck 2 Berserk Gorilla 2 Book of Life 1 Book of Moon 1 Bottomless Trap Hole 1 Compulsory Evacuation Device 1 Creature Swap 1 D.D

By the way, if he Special Summons this card with battles damage, he can't use Abyss because it's the damage step
They're a mid/high level normal monster with a reasonably high attack, and the highest level monster that can be summoned with Elegant Egotist
To give you a head start on how to play Pokemon cards, lets run through the following sections