Well technically the FINAL battle comes at the end of the millenial reign when Satan is loosed to disturb the nations again “for a season”. Unfortunately the Bible indicates that a great mass of humanity will rise up against The new Jerusalem and the Saints. At that point God “pulls the rug out from under temporal normality” and the final judgment occurs.
The little detail about the father of the girl who was reported to have visited Heaven fighting in Armageddon could be true whether or not he personally dies prior to Armageddon. This is because all the saints (saved Christians) are scheduled to show up there, en masse. It will, in a sense, be an unfair fight, a cake walk, but also a satisfying end to history.
My reading puts Armageddon at the end of the 7 year Great Tribulation.
The one at the end of the Millenial reign is not mentioned much at all and only extremely vaguely.