Activate Woe Strider by sacrificing Shambling Ghast.
When Shambling Ghast dies, it and Rakdos trigger.
Resolve the Shambling Ghast trigger, creating a Treasure token.
Activate the Treasure by tapping and sacrificing it, adding .
Holding priority, activate Haunted Crossroads by paying , putting Shambling Ghast from your graveyard onto the top of your library.
Resolve the Rakdos trigger, exiling Shambling Ghast from the top of your library with the ability to cast it until your next turn.
Resolve the Woe Strider ability, causing you to scry 1.
Cast Shambling Ghast from exile by paying 1.
Birgi triggers, adding .
Repeat.
This intricate loop turns Woe Strider and Rakdos, the Muscle into a relentless sacrifice engine, using Shambling Ghast as the recurring fuel that feeds the fire. Every time Shambling Ghast meets its end, it obligingly spawns a Treasure token to fund Haunted Crossroads, which conveniently places the Ghast right back on top of your library where Rakdos can exile it for free casting. Meanwhile, the mana-generating prowess of Birgi, God of Storytelling ensures you stay flush with red mana every time you replay the Ghast from exile, letting you repeat this entire choreography indefinitely to filter through your library and trigger infinite deaths.