Ilet (Ilat; also Toiyoi) is the Kalenjin/Nandi god-being of thunder, rain and lightning, who inhabits deep pools and waterfalls and whose discarded garments are the rainbow. Authored as a numen, era 'mythic'. He is the overarching thunder being whose dual nature is individuated among the Nandi into the good and evil thunders (kalenjin_ilet_ne_mie, kalenjin_ilet_ne_ya), wired here as his two 'aspect' beings (reciprocated on each). No kin edge is asserted to Asis: the sources name Asis and Ilat as the two principal deities side by side but attest no genealogical link between them.
Domains
thunder
rain
lightning
waters
Powers
Hurls the lightning as a sword from the storm
Casts off the rainbow as his discarded garments
Settles boundary and truth disputes by the lightning-stroke
A. C. Hollis, The Nandi: Their Language and Folk-lore (Clarendon Press, 1909)
G. W. B. Huntingford, The Nandi of Kenya: Tribal Control in a Pastoral Society (1953)
'Nandi and Other Kalenjin Peoples', culture summary (HRAF / Encyclopedia.com): 'Ilat is associated with thunder and rain … the rainbow are his discarded garments.'