Like there's many Santa Clauses, there's many Reapers. Roy is the one that resides over at Lake Bodom (except for a visit to New York(?) that lasted from 2003-2011) and his job is to claim all the lonely drunkards lost around the lake, the ones that are subconsciously drawn to it. The lake is just kind of symbolism for the Abyss and the dark comforts and powers it gives at the moment of despair (the "comfort" of suicide, the blissful blur of alcohol, the power of blind rage, etc), but it's not easy to get your soul back once you lose it there. He doesn't bother innocent souls, however, only the fucked up ones and those too disturbed/mistreated to fit into the normal life.