I think 10kg of muscle in 3 months is not doable even if your weight training and eating are on point. You would prob have to drop the mma training a great deal as well.
Even with gear you may gain the weight but it will be mostly water.
can you post a pic? What do your weight training days look like?
@rememberTHE5 might be able to give you some direction on the training/Diet as she is a fighter as well. Check out her log.
Sorry, don't want to post a pic. Leg day is leg extensions, leg curls, bicycle sprint. I wanna add squats and deadlifts, but need to buy a pad for a barbell. Back day is lat pull-down, pull ups, low seated row. Arm day is Scott biceps curl machine, triceps pull down, shoulder press machine, bench press and peck deck. I mix them sometimes, when don't have a time for each day.