Card

Peer into the Abyss

Mana cost {4}{B}{B}{B}

Target player draws cards equal to half the number of cards in their library and loses half their life. Round up each time.

Part of 38 known combos, 22 of them two-card. 2 official rulings.

Bracket

B1 Exhibition — Not in the same deck as its two-card combo partners: Sheoldred, the Apocalypse, Orcish Bowmasters, Underworld Dreams, Psychosis Crawler, Nekusar, the Mindrazer, Razorkin Needlehead, Ob Nixilis, the Hate-Twisted, Bloodletter of Aclazotz, Alhammarret's Archive, Teferi's Ageless Insight, Psychic Corrosion, Folio of Fancies, Black Vise, Feast of Sanity, Vnwxt, Verbose Host, Astarion, the Decadent, Blitzwing, Cruel Tormentor // Blitzwing, Adaptive Assailant, Twenty-Toed Toad, Thought Reflection, Aether Syphon, Bard, King of Dale, Eruth, Tormented Prophet
B2 Core — Not in the same deck as its two-card combo partners: Sheoldred, the Apocalypse, Orcish Bowmasters, Underworld Dreams, Psychosis Crawler, Nekusar, the Mindrazer, Razorkin Needlehead, Ob Nixilis, the Hate-Twisted, Bloodletter of Aclazotz, Alhammarret's Archive, Teferi's Ageless Insight, Psychic Corrosion, Folio of Fancies, Black Vise, Feast of Sanity, Vnwxt, Verbose Host, Astarion, the Decadent, Blitzwing, Cruel Tormentor // Blitzwing, Adaptive Assailant, Twenty-Toed Toad, Thought Reflection, Aether Syphon, Bard, King of Dale, Eruth, Tormented Prophet
B3 Upgraded — allowed: Its two-card combos are not early, which Bracket 3 allows
B4 Optimized — allowed: No restriction beyond the banned list
B5 cEDH — allowed: No restriction beyond the banned list

Two-card combo with Sheoldred, the Apocalypse, Orcish Bowmasters, Underworld Dreams, Psychosis Crawler, Nekusar, the Mindrazer, Razorkin Needlehead, Ob Nixilis, the Hate-Twisted, Bloodletter of Aclazotz, Alhammarret's Archive, Teferi's Ageless Insight, Psychic Corrosion, Folio of Fancies, Black Vise, Feast of Sanity, Vnwxt, Verbose Host, Astarion, the Decadent, Blitzwing, Cruel Tormentor // Blitzwing, Adaptive Assailant, Twenty-Toed Toad, Thought Reflection, Aether Syphon, Bard, King of Dale, Eruth, Tormented Prophet (none of them early)

Bracket: Lotus Vault analysis, with Commander Spellbook flags

38 known combos, 22 of them two-card.

Sheoldred, the Apocalypse + Peer into the Abyss
Produces: Near-infinite card draw for target opponent, Near-infinite draw triggers for target opponent, Near-infinite lifeloss for target opponent
View on Commander Spellbook
Orcish Bowmasters + Peer into the Abyss
Produces: Infinite +1/+1 counters on a creature, Near-infinite card draw for target opponent, Near-infinite damage
View on Commander Spellbook
Peer into the Abyss + Underworld Dreams
Produces: Target opponent loses the game
View on Commander Spellbook

2020-06-23 · Wizards of the Coast
The life lost is rounded up, not the remaining life total. For example, if the target player has 7 life, they lose 4 life and end up with 3. Similarly, the number of cards drawn is rounded up, not the number of cards remaining in the library.
2020-06-23 · Wizards of the Coast
To draw the cards, first the player determines how many cards to draw, then draws them. This event may be modified so that a different number of cards are actually drawn.

Rulings: Scryfall · Wizards of the Coast