I may decide to use AI and OU as additional vowel combinations in Illunse. Neither combination appears in Latin or Old English words.
In Illunse, pronounce ai as in aisle. In Latin this diphthong is spelled ae, but I'm already pronouncing ae as æ in Old English.
In Illunse, pronounce ou as oo in pool, or u in rule. This is like the Latin ū (u macron) and the Old English ú (long u). In Middle English ou was often used to represent this sound.