In a joint effort with his alliance, Heinreich masqueraded as the people of the Patreus alliances and crushed the overall battlefield and won the war. It was intended, even from before, that the armies he showed were just militias.
The thing to do was to invade straight into Villenus. But when they did that, there was nothing much of its western from and all forces were relocated somewhere else. That is the mystery of war is that something you want doesn't actually happen.
Then, when they invaded to Villenus, the coastal invaders arrived. Only that, Heinreich's alliances was raiding towns at Allied dispositions of the Patreus League that they cannot send much of their forces to assist. Thereby not all crystals were used in the teleportation. it was chaos and a total mess.
Stuck with this dilemma, and nearly crushing in all fronts. Abraham now, knowing the truth that he is good at diversionary tactics. Have concluded that Heinreich is the one that attacked him in that time that they were camping in Patreus.
By this time, decided to loop back in time by unlocking the seals in his left hand. By doing so, he travelled back in time during the academy days that might win him the war and change fate from Heinreich.
The time of the travel is on age 16, a moment in the academy that they were at their peak of knowledge and application of experience.