Knightmare Mermaid [FLOD-EN043] Rare

1 "Knightmare" monster, except "Knightmare Mermaid"
If this card is Link Summoned: You can discard 1 card; Special Summon 1 "Knightmare" monster from your Deck, then if this card was co-linked when this effect was activated, you can draw 1 card. You can only use this effect of "Knightmare Mermaid" once per turn. All monsters on the field lose 1000 ATK/DEF, except co-linked monsters.