Activate Phyrexian Devourer by paying {0}, exling the top card of your library and putting a number of +1/+1 counters on Phyrexian Devourer equal to that card's mana value.
If Phyrexian Devourer's power becomes seven or greater this way, it triggers.
Holding priority, repeat from step 1 until you have an empty library.
Resolve the first Phyrexian Devourer trigger, causing you to sacrifice it.
When Phyrexian Devourer leaves the battlefield, The Ozolith's first ability triggers, putting a number of +1/+1 counters on The Ozolith equal to the number Phyrexian Devourer had.
At the beginning of your combat phase, The Ozolith's second ability triggers, moving all counters from it onto Hallar.
Cast any kicker or multikicker spell with kicker by paying its mana cost plus its kicker cost.
Hallar triggers, putting a +1/+1 counter on itself, then dealing damage equal to the number of +1/+1 counters on it to each opponent.

Exile your library

Near-infinite +1/+1 counters on Hallar

Near-infinite damage

Hallar, the Firefletcher

Phyrexian Devourer

The Ozolith

Activate Phyrexian Devourer by paying {0}, exling the top card of your library and putting a number of +1/+1 counters on Phyrexian Devourer equal to that card's mana value.
If Phyrexian Devourer's power becomes seven or greater this way, it triggers.
Holding priority, repeat from step 1 until you have an empty library.
With the Phyrexian Devourer triggers on the stack, cast Slippery Bogbonder by paying {3}{G}.
When Slippery Bogbonder enters the battlefield, it triggers, moving all +1/+1 counters from Phyrexian Devourer onto Hallar.
Resolve all Phyrexian Devourer triggers from step 2, causing you to sacrifice it.
Cast any kicker or multikicker spell with kicker by paying its mana cost plus its kicker cost.
Hallar triggers, putting a +1/+1 counter on itself, then dealing damage equal to the number of +1/+1 counters on it to each opponent.

Slippery Bogbonder

Cast Body of Research by paying {G}{G}{G}{U}{U}{U}, creating a 0/0 Fractal creature token, then putting a number of +1/+1 counters on it equal to your deck size.
Cast Bioshift by paying {G/U}, moving all +1/+1 counters from the Fractal onto Hallar.
The Fractal dies as a state-based action due to having zero toughness.
Cast any kicker or multikicker spell with kicker by paying its mana cost plus its kicker cost.
Hallar triggers, putting a +1/+1 counter on itself, then dealing damage equal to the number of +1/+1 counters on it to each opponent.

Body of Research

Bioshift

Cast Body of Research by paying {G}{G}{G}{U}{U}{U}, creating a 0/0 Fractal creature token, then putting a number of +1/+1 counters on it equal to your deck size.
Cause the Fractal to leave the battlefield.
The Ozolith's first ability triggers, putting a number of +1/+1 counters on The Ozolith equal to the number the Fractal had.
At the beginning of your combat phase, The Ozolith's second ability triggers, moving all counters from it onto Hallar.
Cast any kicker or multikicker spell with kicker by paying its mana cost plus its kicker cost.
Hallar triggers, putting a +1/+1 counter on itself, then dealing damage equal to the number of +1/+1 counters on it to each opponent.

Activate Phyrexian Devourer by paying {0}, exling the top card of your library and putting a number of +1/+1 counters on Phyrexian Devourer equal to that card's mana value.
If Phyrexian Devourer's power becomes seven or greater this way, it triggers.
Holding priority, repeat from step 1 until you have an empty library.
Resolve the first Phyrexian Devourer trigger, causing you to sacrifice it.
When Phyrexian Devourer leaves the battlefield, Resourceful Defense triggers, putting a number of +1/+1 counters on Hallar equal to the number Phyrexian Devourer had.
Cast any kicker or multikicker spell with kicker by paying its mana cost plus its kicker cost.
Hallar triggers, putting a +1/+1 counter on itself, then dealing damage equal to the number of +1/+1 counters on it to each opponent.

Resourceful Defense

Activate Phyrexian Devourer by paying {0}, exling the top card of your library and putting a number of +1/+1 counters on Phyrexian Devourer equal to that card's mana value.
If Phyrexian Devourer's power becomes seven or greater this way, it triggers.
Holding priority, repeat from step 1 until you have an empty library.
With the Phyrexian Devourer triggers on the stack, cast Bioshift by paying {G/U}, moving all +1/+1 counters from Phyrexian Devourer onto Hallar.
Resolve all Phyrexian Devourer triggers from step 2, causing you to sacrifice it.
Cast any kicker or multikicker spell with kicker by paying its mana cost plus its kicker cost.
Hallar triggers, putting a +1/+1 counter on itself, then dealing damage equal to the number of +1/+1 counters on it to each opponent.

Cast Body of Research by paying {G}{G}{G}{U}{U}{U}, creating a 0/0 Fractal creature token, then putting a number of +1/+1 counters on it equal to your deck size.
Cause the Fractal to leave the battlefield.
Resouceful Defense triggers, putting a number of +1/+1 counters on Hallar equal to the number the Fractal had.
Cast any kicker or multikicker spell with kicker by paying its mana cost plus its kicker cost.
Hallar triggers, putting a +1/+1 counter on itself, then dealing damage equal to the number of +1/+1 counters on it to each opponent.

Combos with "Hallar, the Firefletcher"