When Karmic Guide dies, Body Launderer's first ability triggers, causing Body Launderer to connive.
Resolve the Woe Strider ability.
Activate Woe Strider by sacrificing Body Launderer.
When Body Launderer dies, its second ability triggers, returning Karmic Guide from your graveyard to the battlefield.
When Karmic Guide enters, it triggers, returning Body Launderer from your graveyard to the battlefield.
Resolve the Woe Strider ability.
Repeat.
This clever loop revolves around a perpetual cycle of sacrifice and resurrection between Karmic Guide and Body Launderer, both kept cycling with the help of Woe Strider. Whenever Karmic Guide enters the battlefield, its triggered ability pulls Body Launderer right back from the graveyard, while sacrificing Body Launderer in turn triggers its own death ability to bring Karmic Guide back. Woe Strider acts as the ultimate engine for this loop, providing a reliable sacrifice outlet while letting you filter through your deck with infinite scrys and the connive triggers from Body Launderer.