kei reira (katoa)!
1. that's the one! right on! she's/he's got it! it's his/her strong point! it's his forte! fabulous!, awesome - an idiom used to praise someone's ability.
(Te Kōhure Textbook (Ed. 2): 196;)
Kua kite koe i a Tarati e pūkana ana? Āna, e hoa. Kei reira! / Have you seen Dorothy doing the pūkana? Yes, indeed, my friend. It's her forte!
Synonyms: kei konā (katoa)!
reira
1. (location) the place, time or circumstance mentioned before, that place, there - a location word, or locative, that acts like a pronoun for place names. Follows immediately after particles such as ki, i, hei and kei or is preceded by a when used as the subject of the sentence.
He tipuna nō mātau nō Te Whāiti. Ko tō mātau hapū o reira ko Ngāti Whare. / We have relations from Te Whāiti. Our hapū there is Ngāti Whare.