Marked with the Sigil of Lucifer, Luke travelled through a gateway to Hell to close it forever. Trapped within Hell, him and his Unknown companion had to make their way through hordes of Unknowns, Unknowns, and Unknowns to get to the 666th Layer of Hell to meet with Lucifer to get a drop of Tempus's blood so that Seralindra could find a way to Veilshadow's Time Flux.
Due to the time dilation effects of Tempus being within Hell, Lukano had to time his travel between layers perfectly but it required over three and a half years to reach Lucifer and return to Drokhan.