偉烈[iretsu] great achievement
苛烈[karetsu] severe
強烈[kyouretsu] strong
劇烈[gekiretsu] violence
激烈[gekiretsu] violent

酷烈[kokuretsu] severity
鮮烈[senretsu] vivid
壮烈[souretsu] heroic
痛烈[tsuuretsu] severe
熱烈[netsuretsu] ardent

熾す[okosu] to light a fire
熾烈[shiretsu] fierce
熾火[okibi] glowing ember (either red hot charcoal or the glowing remains of burnt firewood)

熾きる[okiru] to be kindled (fire)
熾熱[shinetsu] intense heat