Article snapshot taken from Wikipedia with creative commons attribution-sharealike license.
Give it a read and then ask your questions in the chat.
We can research this topic together.
It was built to a Russian Revival design by Yevhen Yermakov [uk] between 1905 and 1912. The building is pentacupolar, with the massive black central dome and the four tent-like domes on the corners, as well as low galleries which run continuously around the building. The outer walls are covered with a mazy web of tracery.
The hollow shell of the church was returned to the Ukrainian Orthodox Church in 1990s and has been restored as the main church of a nunnery. The other church building of the convent conforms to the cathedral in style.