Aurelia, the Law Above

Flying, vigilance, haste
Whenever a player attacks with three or more creatures, you draw a card.
Whenever a player attacks with five or more creatures, Aurelia, the Law Above deals 3 damage to each of your opponents and you gain 3 life.

Demand Answers

As an additional cost to cast this spell, sacrifice an artifact or discard a card.
Draw two cards.

Rakdos, Patron of Chaos

Flying, trample
At the beginning of your end step, target opponent may sacrifice two nonland, nontoken permanents. If they don't, you draw two cards.

Deduce

Draw a card. Investigate. (Create a Clue token. It's an artifact with "{2}, Sacrifice this artifact: Draw a card.")

Lead Pipe

Equipped creature gets +2/+0.
Whenever equipped creature dies, each opponent loses 1 life.
{2}, Sacrifice Lead Pipe: Draw a card.
Equip {2}

Not on My Watch

Wojek Investigator

Flying, vigilance
At the beginning of your upkeep, investigate once for each opponent who has more cards in hand than you. (To investigate, create a Clue token. It's an artifact with "{2}, Sacrifice this artifact: Draw a card.")

Out Cold

This spell can't be countered. (This includes by the ward ability.)
Tap up to two target creatures and put a stun counter on each of them. Investigate. (If a permanent with a stun counter would become untapped, remove one from it instead.)