Defiler of InstinctHow it works & interactions with other cards

Paid in Blood

While Defiler of Instinct is on the battlefield, you gain a special payment option for every red permanent spell you cast. You may choose to pay 2 life as an additional cost; if you do, the cost of that spell is reduced by one red mana ({R}). Note that this reduction only applies to the red portion of the mana cost, not generic costs, and you can only perform this life-for-mana swap once per spell.

Triggering Damage

Every time you cast a red permanent spell, Defiler of Instinct's triggered ability goes on the stack. It deals 1 damage to any target, which includes players, planeswalkers, or creatures. This trigger happens whether or not you chose to pay life for the mana reduction, as long as the spell being cast is both red and a permanent type (like a creature, enchantment, or artifact).

The 'Phyrexian' Shortcut

Many players mentally treat this ability as giving spells a Phyrexian Mana symbol, but technically it is an additional cost and a cost reduction. This is an important distinction for cards that specifically check for Phyrexian symbols. Additionally, if a spell's cost is already reduced by other effects, you can still pay the 2 life to reduce the remaining red mana required.

Strategic Timing

Because the damage triggers 'on cast,' the 1 damage is dealt before the red permanent spell actually enters the battlefield. This makes it excellent for picking off small blockers or finishing off a weakened planeswalker before your new threat even arrives on the scene.

Interaction examples

Doubling the Instinct

Roaming Throne

If you cast Roaming Throne and choose 'Phyrexian' or 'Kavu' as its type, it becomes that type in addition to its others. Now, whenever you cast another red permanent spell, Defiler of Instinct's ability triggers. Roaming Throne sees this trigger from another creature of the chosen type and causes it to trigger an additional time, allowing you to deal 1 damage to two different targets (or 2 damage to one target).

Non-Red Interactions

Solemn Simulacrum

If you cast Solemn Simulacrum while Defiler of Instinct is on the battlefield, you cannot pay 2 life to reduce its cost. Because Solemn Simulacrum is a colorless artifact spell, it does not meet the requirement of being a 'red permanent spell.' Furthermore, no damage will be dealt by the Defiler's triggered ability for the same reason.