Ye Fan, deducing from the available information, surmised that with each tier increase in the Overlord Mode, the overall duration of the mode would extend beyond the initial 5 minutes. This extension was likely achieved by mitigating the strain on the user's body, reflecting a progression that sought to enhance both the effectiveness and sustainability of the Overlord Mode. It's more like optimizing the already powerful Skill and strengthening it so that the user can exert more power with less strain and spiritual power.