In the wake of All Might's rejection, Izuku goes with Sensei. The League gained a new member, and the future shifted.
As Kurogiri knows, Sensei has many quirks and many plans, embodied in those he chooses to invite into the League. As someone near the centre of the League, Kurogiri knows more about their aspects than anyone except Sensei. He knows how the ancient man covers every angle of the situation, even the ones no one else saw coming. Sensei was always prepared to play the long game.
Tomura Shigaraki was one plan. The obvious plan. The one everyone focuses on.
Izuku Midoriya was an unexpected plan, a hidden plan, one that bides its time before striking when you least expect it.
Both men have power and purpose, but only one needs to succeed. Kurogiri watches both plans unfold, from their joined beginnings, through their diversion, until they meet again, in a world they changed.
Spanish Translation https://www.wattpad.com/story/232714891-another-form-of-power