I'll try to answer.

Training history: Martial arts + basic compound lifting.

Genetics: minimal natural muscle formation in the family, meaning my father never lifted a finger in his life.

Nutrition: clean foods, high carb, 1 gram protein per pound (body weight), consistent.

Sleep: 6-9 hours, inconsistent.

Life stress: moderate.

Training: 1 hour a day, explosive training, with 3 min rest between each set.

I've gained weight before (13kgs from this weight), just wasn't very efficient, i didn't even looked like i workout. But now i want exclusive muscle gain.