You have a card in hand with kicker or multikicker.
You have enough mana to cast the kicker spell kicked.
Steps
Activate Phyrexian Devourer by paying ({0} magic symbol) , 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.