Card

Silverclad Ferocidons

Mana cost {5}{R}{R}

Enrage — Whenever this creature is dealt damage, each opponent sacrifices a permanent of their choice.

Part of 2 known combos, one of them two-card. 4 official rulings.

Bracket

B1 Exhibition — Not in the same deck as its two-card combo partner: Mayhem Devil
B2 Core — Not in the same deck as its two-card combo partner: Mayhem Devil
B3 Upgraded — Not in the same deck as its early two-card combo partner: Mayhem Devil
B4 Optimized — allowed: No restriction beyond the banned list
B5 cEDH — allowed: No restriction beyond the banned list

Bracket: Lotus Vault analysis, with Commander Spellbook flags

2 known combos, one of them two-card.

Silverclad Ferocidons + Mayhem Devil
Produces: Each opponent sacrifices all permanents they control, Near-infinite damage, Mass Land Denial
View on Commander Spellbook
Ghyrson Starn, Kelermorph + Temple Altisaur + Silverclad Ferocidons + Spark Double
Produces: Each opponent sacrifices all permanents they control, Mass Land Denial
View on Commander Spellbook

2018-01-19 · Wizards of the Coast
When Silverclad Ferocidons's triggered ability resolves, first the player whose turn it is (if that player is an opponent) chooses which permanent they will sacrifice, then each other opponent in turn order does the same, then all chosen permanents are sacrificed at the same time. Players will know choices made by earlier players when making their choices.
2018-01-19 · Wizards of the Coast
If creatures an opponent controls are dealt lethal damage at the same time that Silverclad Ferocidons is dealt damage, those creatures will be destroyed before that player chooses a permanent to sacrifice.
2018-01-19 · Wizards of the Coast
If multiple sources deal damage to a creature with an enrage ability at the same time, most likely because multiple creatures blocked that creature, the enrage ability triggers only once.
2018-01-19 · Wizards of the Coast
If lethal damage is dealt to a creature with an enrage ability, that ability triggers. The creature with that enrage ability leaves the battlefield before that ability resolves, so it won't be affected by the resolving ability.

Rulings: Scryfall · Wizards of the Coast