It turns out -- as many readers had surmised, given the available clues -- that the "Helmet of Fate" that was leading Ralph around was actually Felix Faust, who was on a mission to obtain Ralph's soul and hand it over to Neron in exchange for his own freedom. Ralph, being no fool (and a pretty good detective), had doped this out too, which scotched the plan, even as Neron showed up inside the binding circle that Ralph had cast.
And Neron, never the brightest of demons, proceeded to kill Ralph without thinking about the fact that only Ralph could drop the binding circle that would keep Neron and Faust imprisoned together for eternity.
I suspect, however, that Ralph has a "Get Out of Death Free" card. If Neron could revive Sue, he could equally well revive Ralph if Ralph were willing to be revived. And Ralph would no doubt be willing to be revived if Sue were too.
Heck, he'd probably even be willing to drop that nasty binding circle. All we need to do is wait for Neron (never the brightest of demons) to figure this out, which he'll probably do once he gets over throwing his temper tantrum all over Faust's immortal soul. :)
And Dan Didio said at today's NY ComicCon that there's still more to Ralph's story that needs to be told...