Nexus' mission in life is to (unwillingly) seek out and kill mass murderers (A superhero who actually kills baddies?!). The Merk inform him on who his targets are via visions & dreams which can turn into nasty nightmares which can actually physically injure him. These scans of a shirtless & speedo-clad Horatio Hellpop are from Nexus Vol. 2 #4.
Bonus: Gratuiutous Horatio Hellpop Butt-shot.