{O Lord God} (Kurie ho theos). Vocative form kurie and
nominative form ho theos (vocative in use). See  1:8  4:8  for
this combination with ho pantokrat(9372) (the Almighty). For ho (936e)
kai ho (886e) (which art and which wast) see  1:4,8  4:8  16:5 .
{Thou hast taken} (eil(8870)hes). Perfect active indicative of
lamban(935c), emphasizing the permanence of God's rule, "Thou hast
assumed thy power." {Didst reign} (ebasileusas). Ingressive
first aorist active indicative of asileu(935c), "Didst begin to
reign." See this combination of tenses (perfect and aorist)
without confusion in  3:3  5:7  8:5 .