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"An urban fantasy / sci-fi novel from the late 1990s set in the UK. The male MC had tremendous powers but did not know how to use them well and a conspiracy was out to stop him and his band of misfits. I believe there was a black Jamaican character named Tregammon (or something similar as a slang term for triggerman). The cover was I believe mostly blue with a blueish/silver outline of a man with lightning effects around it. a final climactic battle where the MC uses his reality powers A jamaican hitman in London scifi"