Solphim, Mayhem Dominus is one of those cards players keep asking about. Here is, in plain words, what its official text says, the rulings published by Wizards of the Coast, and the combos players actually run.

Official card text

If a source you control would deal noncombat damage to an opponent or a permanent an opponent controls, it deals double that damage to that player or permanent instead. , Discard two cards: Put an indestructible counter on Solphim. ( can be paid with either or 2 life.)

Complete guide

Solphim, Mayhem Dominus is a powerhouse in aggressive red decks, acting as a multiplier for all your burn spells and noncombat effects. It punishes opponents by doubling damage output while offering a resilient body that can gain indestructible at any time. Mastering its replacement effect is key to dominating the board and ending games quickly.

Understanding the Damage Multiplier

Solphim features a replacement effect that modifies how noncombat damage is dealt. If a source you control—whether it is a spell like a fireball or an ability from a creature—would deal damage to an opponent or their permanents, Solphim doubles it. This effect does not use the stack and cannot be responded to once the damage-dealing event begins. Note that this only applies to noncombat damage; combat damage dealt by creatures during the combat phase remains unchanged.

Gaining Indestructible

Solphim can protect itself using its activated ability. By paying one generic mana and two Phyrexian red mana (which can be paid with four life total if you lack red mana), and discarding two cards, you place an indestructible counter on it. Because this uses a counter, Solphim remains indestructible even if it loses its abilities later, provided the counter stays on the permanent.

Interaction with Multiple Effects

If multiple effects would modify how damage is dealt, the player being dealt the damage or the controller of the permanent being dealt damage chooses the order in which those effects apply. However, since Solphim simply doubles the result, applying it usually results in the same outcome unless there are damage prevention shields or other additive modifiers involved.

When to Deploy Solphim

The best time to play Solphim is right before you plan to unleash a flurry of burn spells or activated abilities. Since it is a legendary creature, having multiple copies on the field is restricted by the legend rule, but its high toughness and the ability to gain indestructible make it a difficult threat for opponents to remove once it hits the battlefield.

Interaction examples

Solphim and Triggered Multipliers

Roaming Throne

If you control Roaming Throne and choose 'Phyrexian' or 'Horror', it will not double Solphim's damage effect because Solphim's first ability is a static replacement effect, not a triggered ability. However, if Solphim had a triggered ability (starting with 'When', 'Whenever', or 'At'), Roaming Throne would cause it to trigger an additional time.

Value and Defense

Solemn Simulacrum

While Solphim doubles noncombat damage, it does not affect Solemn Simulacrum's enter-the-battlefield or death triggers as they do not deal damage. However, you can use the card drawn from Solemn Simulacrum's death trigger to help pay the 'discard two cards' cost for Solphim's activated ability to gain an indestructible counter.

Direct Burn Example

If you control Solphim and cast a spell that deals 3 damage to an opponent, Solphim's static ability sees this event. Before the damage is dealt, the effect is replaced with 6 damage. The opponent takes 6 damage in a single instance.

Guide written with AI from the official text and rulings. Official English text prevails.