I couldn't miss the chance to practice my drawing!
Poison Blade (ポイズン剣, Poizun Ken?), also known as Poison Sword, Putrid Slash, or simply Poison or Venom, is a recurring ability in the series. It is generally a mid-powered Poison-elemental Spellblade ability, either giving the user the element or status as long as they don't use another Spellblade ability or outright dealing damage. It generally requires the Poison spell in order to use it.
Poison is a level 2 Spellblade ability that costs 1 MP to cast. When used against an enemy that is weak to Poison-elemental attacks, the power of the user's attack is doubled and pierces the target's defenses.
Poison Blade is a rank 1 Command Materia that costs 6 AP to use. It can be obtained by completing Mission 4-1-6, stealing or winning it from Scissor Claw, or finding it in Missions 7-4-5 and 9-3-2. Poison Blade is a physical attack that inflicts Poison.
Poison is a level 2 Sword Magic. It imbues a weapon with the status ailment poison for ten turns and has a 75% chance to cause poison in one target when attacking. It costs 4 MP to use. It can be bought in Ancheim for 400 pg.
Putrid Slash is an ability of the Magic Blade skillset, usable by the Red Mage class. It costs 8 MP to use and inflicts physical damage and Poison to one target.