yugioh cards link Yu-Gi-Oh! - Disciple - DUPO-EN070 - Ultra Rare - 1st Edition Once per turn Link Monster - Yugipedia

If a Normal Trap Card is activated (except during the Damage Step): You can detach 1 material from an Xyz Monster you control, and if you do, Special Summon 1 Level 4 monster from your hand

Currently, it is used occasionally in dragon-type decks that use the phoenix dragon

If you know of any other particularly weird cards, then feel free to talk about them in the comments down below.

In an archetype where you make XYZ monsters using only one monster, this means you can do a ridiculous amount of combos

When a face-up Attack Position monster your opponent controls just activated an effect (except during the Damage Step): Negate that effect, and if you do, change that monster to face-up Defense Position

However, they have one sick burn card that drains your opponent of half their life points