An opponent that is unable to block and kill Port Razer controls a planeswalker with three or less loyalty counters on it.
Steps
Activate Dovin by removing a loyalty counter from it, preventing all damage done to and done by an opponent's planeswalker with three or less loyalty counters on it until your next turn.
At the beginning of your combat phase, Odric triggers, giving creatures you control haste, trample and trample over planeswalkers until end of turn.
Declare Port Razer as an attacker, attacking the planeswalker targeted by Dovin in step 1.
Deal combat damage to the planeswalker's controller due to Port Razer's trample over planeswalkers.
Port Razer triggers, untapping all creatures you control and giving you an additional combat phase after this one.