When Leonin Relic-Warder enters, its first ability triggers, exiling Rescue Skiff.
Activate Woe Strider by sacrificing Leonin Relic-Warder.
When Leonin Relic-Warder dies, its second ability triggers, returning Rescue Skiff from exile to the battlefield.
When Rescue Skiff enters, it triggers, returning Leonin Relic-Warder from your graveyard to the battlefield.
When Leonin Relic-Warder enters, its first ability triggers, exiling Rescue Skiff.
Resolve the Woe Strider ability from step 3.
Repeat from step 3.
This clever loop hinges on a self-sustaining cycle of displacement and resurrection between Leonin Relic-Warder and Rescue Skiff. Every time Leonin Relic-Warder enters the battlefield, it exiles Rescue Skiff, which immediately triggers Rescue Skiff's own entry ability to haul Leonin Relic-Warder right back out of the graveyard. Woe Strider acts as the sacrificial outlet that kicks off this endless engine by sending Leonin Relic-Warder to the graveyard in the first place, letting you continually rake in infinite sacrifice, death, and entering-the-battlefield triggers while filtering your draws with endless scrys.