Gem-Knight Quartz

Single card

When your opponent controls a monster, you can discard Gem-Knight Quartz to set a "Fusion" Continuous Spell directly from your deck. However, this comes with a restriction: you cannot Special Summon monsters from your Extra Deck (except for Gem-Knight monsters) for the rest of the turn. 

When Gem-Knight Quartz is used as Fusion Material and sent to the Graveyard or banished, you can add one other Gem-Knight monster from your Graveyard to your hand. This effect helps recycle your resources and can be crucial for further Fusion Summons.