In fact, I can't even find a single Mythic Rare for which I can create an argument against its Mythicness by Wizards 's stated criteria
C Common Marincess Wonder Heart X WATER Link 4 [ CyberseLinkEffect ] ATK 2400 DEF - 2+ WATER monsters Once per battle, during damage calculation, if this card battles a monster (Quick Effect): You can Special Summon 1 of your "Marincess" Monster Cards equipped to this card, also this card cannot be destroyed by that battle, and you take no battle damage from that battle
#9 Psyduck Master Ball Mirror (10,800 / ~$73) Psyducks meme-tier popularity drives serious demand
UR Ultra Rare UL Ultimate Rare The Grand Spellbook Tower X SPELL Field Once per turn, during your Standby Phase, if you have a Spellcaster-Type monster on your side of the field or in your Graveyard: You can place 1 "Spellbook" Spell Card from your Graveyard on the bottom of your Deck, except "The Grand Spellbook Tower", then draw 1 card
The chance of hitting my fourth-turn land drop with a three-land hand is over 90%