Cast Harmless Offering by paying {2}{R}, giving control of Colfenor's Plans to an opponent.
Whenever the opponent that controls Colfenor's Plans casts a spell from their hand, Knowledge Pool triggers, exiling that spell.
Because Colfenor's Plans prevents the opponent from casting more than one spell each turn, the opponent cannot cast the spell permitted by Knowledge Pool, or any other spell that turn.

Exile all spells target opponent casts from their hand

Target opponent can only cast one spell per turn

Target opponent skips their draw step

Lock

Knowledge Pool

Colfenor's Plans

Harmless Offering

Cast Donate by paying {2}{U}, giving control of Colfenor's Plans to an opponent.
Whenever the opponent that controls Colfenor's Plans casts a spell from their hand, Knowledge Pool triggers, exiling that spell.
Because Colfenor's Plans prevents the opponent from casting more than one spell each turn, the opponent cannot cast the spell permitted by Knowledge Pool, or any other spell that turn.

Donate

Cast Fractured Identity by paying {3}{W}{U}, exiling Colfenor's Plans and causing each opponent to create a token copy of it.
Whenever an opponent casts a spell from their hand, Knowledge Pool triggers, exiling that spell.
Because Colfenor's Plans prevents the opponent from casting more than one spell each turn, the opponent cannot cast the spell permitted by Knowledge Pool, or any other spell that turn.

Exile all spells opponents cast from their hands

Opponents can only cast one spell per turn

Opponents skip their draw steps

Fractured Identity

Activate Zedruu by paying {U}{R}{W}, giving control of Colfenor's Plans to an opponent.
Whenever the opponent that controls Colfenor's Plans casts a spell from their hand, Knowledge Pool triggers, exiling that spell.
Because Colfenor's Plans prevents the opponent from casting more than one spell each turn, the opponent cannot cast the spell permitted by Knowledge Pool, or any other spell that turn.

Combos with "Colfenor's Plans"