well, i think that the renzoku d disc is a good idea but with kaioken, i reckon it should be an attack but it should lower HP rather than KI (as it reduces defence) with this, ur PL increases and speed increases. The higher your base pl is, the more times you can use it. After that, goku shouldnt need to many more attacks. As for gohan's rage that would be an ok idea too. With that, ur PL could increase by say times 2, for about 45 seconds, after that, ur PL decreases by half of your base rate and slowly regenerates to what the base rate is supposed to be.