The Battlefield

Derevi, Empyrial Tactician

$7.15 foil

Emiel the Blessed

$12.11

Mana Vault

$84.59

AI DraftFeb 26, 2026

Derevi, Empyrial Tactician + Emiel the Blessed + Mana Vault

Overview

Using Emiel the Blessed's {3}

activated ability to exile and return Derevi will cause Derevi's enter-the-battlefield trigger to trigger, letting you tap or untap a target permanent such as Mana Vault. You can loop: tap Mana Vault for {C}

, pay

to activate Emiel targeting Derevi, Derevi re-enters and untaps Mana Vault, then tap Mana Vault again for {C}

. Each loop consumes the 3 colorless from Mana Vault to pay Emiel and returns those 3 colorless by tapping Mana Vault again, producing arbitrarily many ETB triggers (and repeated tap/untap actions) with no net mana gain. The loop requires Emiel to target Derevi (it must be “another” creature relative to Emiel) and that Derevi actually enters the battlefield (so Derevi’s triggered ability is created). See , , and the Emiel ruling (2020-06-23) for paying its enter-the-battlefield triggered ability.

Step 1

Ensure you control Emiel the Blessed, Derevi, and Mana Vault and Mana Vault is untapped.

Step 2

Tap Mana Vault for {C}

using its

: Add

ability.

Step 3

Use

of that colorless to activate Emiel the Blessed's {3}

ability, targeting Derevi (Emiel's ability is an activated ability that goes on the stack; see ).

Step 4

Allow Emiel's ability to resolve: it exiles Derevi, then returns Derevi to the battlefield as part of that resolution (the return-to-battlefield effect causes Derevi to be put onto the battlefield and thus creates its ETB trigger; see ).

Step 5

When Derevi enters, its triggered ability is created and goes on the stack; when that trigger resolves choose to untap Mana Vault.

Step 6

With Mana Vault untapped, tap it again for {C}

. You now have the three colorless needed to pay Emiel again, and you can repeat the sequence as many times as you like.

Resolution

You can use Emiel’s {3}

activated ability to exile and return Derevi, creating a Derevi enter-the-battlefield trigger that can untap Mana Vault. By tapping Mana Vault for {C}

and using

of that to activate Emiel, then letting Derevi untap Mana Vault when it re-enters, you can repeat that sequence indefinitely to produce as many ETB triggers and tap/untap events as you want. Emiel’s activated ability is placed on the stack and resolves (see ); the return-to-battlefield is part of that resolution and the Derevi ETB trigger is generated when Derevi is put onto the battlefield (see ). If Emiel’s “another creature enters” triggered ability triggers, you may pay {G/W}

as that triggered ability resolves to put counters on the entering creature (Ruling [2020-06-23]). Note that Derevi’s commander-only activated ability to put Derevi onto the battlefield from the command zone can only be activated while Derevi is in the command zone (Ruling [2020-11-10]) and is not part of this loop unless Derevi is in the command zone.

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