My friend @chethaunts told me about a character from Critical Role, Percival de Rolo, who invented and wields the first gun in the CR universe. I asked "Who would win between him and Jesper." We agreed that Jesper would win because Jesper never misses, and then I got to thinking.
Jesper is overpowered and broken.
This is brilliant in terms of Grisha because Jesper is extremely unorthodox.
The Second Army is restrictive for Grisha, and by never joining the Second Army in-series, Jesper has more freedom. The Grisha have their orders and the colors they wear, but Jesper exists entirely without the structures of the second army. In the first trilogy, the Durasts and Alkemi didn't even fight on the front lines, being relegated to laboratories at the Little Palace. Jesper, a rouge Durast helps Wylan create a drill out of a diamond necklace. Jesper, a rouge Durast controls bullets with his mind. Grisha wouldn't even be an appropriate term at this point, as Jesper is free from the rigidity of the structure of the Second Army. He's not just a rouge Durast, he's zowa, blessed. Blessed by not being in the Second Army and all its restrictions. Jesper has incredible potential because he's free.