plague

Contagious Pirate
DARK Zombie/Plague/Effect
L1 100/600
This card does not lose ATK or DEF from Virus Counters. When this card is Summoned, place 1 Virus Counter on this card. If this card is destroyed by battle: You can target the monster that destroyed this card; place 1 Virus Counter on that card. You can banish this card from your Graveyard, then target 1 Special Summoned monster your opponent controls; place 1 Virus Counter on that target. You can only use each effect of "Contagious Pirate" once per turn.

Contagious Rat
DARK Zombie/Plague/Effect
L4 1000/1000
This card does not lose ATK or DEF from Virus Counters. When this card is Summoned, place 1 Virus Counter on this card. You take no damage from battles involving Plague monsters you control and monsters your opponent controls with Virus Counters on them. If this card would be destroyed, remove 1 Virus Counter from this card instead.

Contagious Swordsman
DARK Zombie/Plague/Effect
L4 1600/1000
This card does not lose ATK or DEF from Virus Counters. When this card is Summoned, place 1 Virus Counter on this card. If your opponent controls only monsters with Virus Counters, this card can attack your opponent directly. If this card inflicts battle damage to your opponent: You can target 1 monster your opponent controls with Virus Counters on it; return that target to the hand.

Contagious Ghoul
DARK Zombie/Xyz/Plague/Effect
R4 2100/1700
2 Level 4 Plague monsters
This card does not lose ATK or DEF from Virus Counters. When this card is Xyz Summoned, place 1 Virus Counter on this card. You can target 1 Plague monster you control and 1 monster your opponent controls; remove 1 Virus Counter from the first target, and if you do, place 1 Virus Counter on the second target. You can detach 1 Xyz Material from this card, then target 2 monsters your opponent controls with Virus Counters on them; remove all Virus Counters from the first target, and if you do, place Virus Counters on the second target, equal to the number of Virus Counters removed from the first target, this way. You can only use each effect of "Contagious Ghoul" once per turn.

Contagious Spread
Normal Spell Card
Send all Set cards you control to the Graveyard, then target 1 monster your opponent controls; place Venom Counters on that target, equal to the number of Set cards you sent to the Graveyard by this effect. You can only activate 1 "Contagious Spread" per turn.