yugioh tour guide from the underworld deck RC04-AE006 (EXSER) also it cannot be used as Synchro Material. From the Underworld - Yugipedia

The successful Burning Vengeance decks run as many cheap flashback cards as they can get their hands on, allowing them to burn up opposing threats as quickly as their opponents can cast them

So, even if your deck has 15 cards in your sideboard, in best-of-one, only 7 cards are accessible

This card can be Xyz Summoned once per turn using 1 Rank 8 Xyz Monster you control

C Common The Agent of Wisdom - Mercury X LIGHT Level 4 [ FairyEffect ] ATK 0 DEF 1700 Once per turn, during your Standby Phase, if you controlled this face-up card in your Monster Zone and had no cards in your hand at the end of the opponent's last turn: Draw 1 card

Its serene design and strategic viability have helped it endure across generations, making it not only a beloved Pokmon among fans but also a tactical choice in many trainers' teams

Common Cards Circle Common Pokemon cards features a small black circle, or a dot located next to the number