In map/battle.c there is this part about Asura Strike aka Extrimity Fist:
case MO_EXTREMITYFIST: #ifndef RENEWAL { //Overflow check. [Skotlex] unsigned int ratio = skillratio + 100*(8 + st->sp/10); //You'd need something like 6K SP to reach this max, so should be fine for most purposes. if (ratio > 60000) ratio = 60000; //We leave some room here in case skillratio gets further increased. skillratio = (unsigned short)ratio; }#endif break;
If you are using pre-renewal ther is an overflow check, so if you are using high rates with high stats your asura will be capped at some point. This is becuase a short int is from 0 to 65535. If you change the cap to more than this you will get an overflow error, which means it will start again from 0.