Yugioh Jeopardy XXV Round 1

My Time Has Come

100

Now recognized as one of the best counter traps in the game, this card was heavily derided at the time of its release, as many players thought its cost was too demanding.

Solemn Judgment

200

Forbidden for a brief period of time, this tuner monster might have lived a quiet life in its casual deck if it weren't for Union Carrier and its ability to lock the extra deck.

Dragon Buster Destruction Sword

300

This zexal-era quick-play spell is best known for its role in Jesse Kotton's Sky Striker deck in 2019, to easily deal up to 10,000 damage in a single attack.

Double or Nothing!!

400

This card from one of the worst 5ds archetypes saw some success in Dragon Ruler format as an easy way to answer Evilswarm Ophion

Genex Ally Duradark

500

This card saw play in OCG Dogmatika Invoked builds, as a giant monster to combo with Invoked Augoides for OTKs or to remove almost any monster in the game with Dogmatika Punishment. The advantage it had over its counterpart was it couldn't be used to make Invoked Mechaba

Five-Headed Dragon

Localization

100

Negalogia AA-Zeus

Divine Arsenal AA-Zeus - Sky Thunder

200

Shambhala the Mediterranean World

The Hidden City

300

Dark Summoning God

Dark Summoning Beast

400

Buster Mode

Assault Mode Activate

500

Savior Demon Dragon

Majestic Red Dragon

Leaving a Mark

100

Prior to the release of this card, the forbidden section of the Forbidden and Limited List did not exist.

Chaos Emperor Dragon - Envoy of the End

200

This card's power as a standalone card was so high, players changed the entire structure of their deck just to counter it.

That Grass Looks Greener

300

Best known for helping to bring about the end of goat format, this card was so good that it was briefly limited from 2008-2009.

Cyber Dragon

400

This monster was so ubiquitous and so powerful that it prompted players to summon their monsters in defense position, lest they get removed.

Number 101: Silent Honor ARK

500

According to TheDuelLogs, this trap card is part of the reason why you set your backrow in Main Phase 2 and is one of the hardest punish to players who don't.

Malevolent Catastrophe

The 50's

100

This monster is the strongest monster in the game to have an ATK that ends in 50

Gate Guardian

200

Known in competitive play like one of her sisters, this card is best known for being paired with Kaijus 

Fairy Tail - Luna

300

In lore, this card was originally a Constellar, though we do know this card's brother, Pollux

Evilswarm Castor

400

Players probably never bothered to look at this card's ATK, as they were too busy ranking up with it into Azathot in the OCG or Cyber Dragon Infinity in the TCG.

Tellarknight Ptolemaeus

500

Eliminate! Eradicate! Exterminate! These are the thoughts of lingering Steelswarm souls, yearning for a body so that they might make their dream a reality

Evilswarm Heliotrope

The Numbers, Mason

100

Big Eye

Number 11

200

Shock Master

Number 16

300

Galaxy-Eyes Tachyon Dragon

Number 107

400

Acid Golem of Destruction

Number 30

500

Illumiknight

Number 10

Examples from the Text

100

Conquistador of the Golden Land

Eldlich the Golden Lord

200

Striker Dragon

Boot Sector Launch

300

Shooting Quasar Dragon

Shooting Star Dragon

400

Koa'ki Meiru Drago

Iron Core of Koa'ki Meiru

500

Water Dragon (3 answers required)

Hydrogeddon, Oxygeddon, Bonding H2O