I'm the Villain's Constellation with Empty Pockets

Gahyeon never expected to find himself inside a novel, let alone as the Constellation of the villain, Taebeom Baek. Determined to prevent the world’s destruction, he decides to sponsor Taebeom and lead him down a righteous path instead, but there’s one problem—he’s broke. As Gahyeon struggles to alter Taebeom’s fate, their bond deepens, and Gahyeon faces a hard truth: his efforts to save the world may push Taebeom toward the very destruction he’s trying to stop.

Source: Tapas