Guess and i'll tell

Four siblings Zoë, Alex, Adrian and Jamison ran away from home and are now working for a boss-type assassin, the catch is; the criminals they are hired to 'deal with' all have some kind of supernatural ability, the quadruplets soon find that they are descendants from the first angels, the archangels.
Not just descendants but the most powerful angels simply cast down to earth to be reborn as human time and time again.
And they are the keys to reuniting heaven to earth, as it has been locked away due to the sins of the angels.
There is no god, the archangel's rule over all angelic kind.