Go to Ex. Skills for kratos or zelos (which everone you have) and give him an ex. gem level 3 (slasher), another level 3(superchain), another level 3(eternal). go battle and then he'll get a new ex skill called super blast which lets him slash 6 times and end off with a tech move. Thats not all now give him an Ex. gem level 1(taunt). This will give him the ex skill
combo force and then your set read combo force and you'll see why its ultimate.