yugioh mausoleum of the emperor deck (Platinum Secret Rare) [RA03-EN167] Platinum Ive just read the errata

You can sort by banned, limited and forbidden cards, as well as switch between different card pools, such as TCG, OCG and Rush

Bottom line, Solid isnt a BAD card, per se, but considering he shares UR materials with the other normal summons of the deck, Stratos and Vyon, which are strictly better than Solid, in my opinion skip him and dont waste your materials

It is one of the most bizarre moments from the first season of Yu-Gi-Oh

The main deck contains exactly 40 cards

Labrynth cards can destroy monsters, spell cards, and trap cards before the opponent gets the chance to use them

If this card is sent from the field to the GY: You can Special Summon 1 Union monster from your hand