"wicked, dissolute wretch; thorough rascal," 1550s (1540s as an adjective), possibly an alteration (by association with rake (n.1) and Hell) of Middle English rakel (adj.) "hasty, rash, headstrong," which is probably from raken "to go, proceed," from Old English racian "to go forward, move, hasten," a word of unknown origin. But the verbal phrase rake Hell "go over (Hell) thoroughly" is attested by 1540s. Compare rakeshame (n.) "one who lives shamefully" (1590s).
Pluto was infernus rex, and Latin inferi meant "the inhabitants of the infernal regions, the dead." Association of the word with fire and heat is via the Christian conception of Hell. Meaning "devilish, hateful" is from early 15c.; meaning "suitable for or appropriate to Hell" is from c. 1600. As a name of Hell, or a word for things which resemble it, the Italian form inferno has been used in English since 1834, via Dante. Related: Infernally.