During the boss battle versus R7308XX you can use the Flea Bags repeatedly; this can get the boss's offense to a point where he cannot kill Eve. The battle will eventually end after 255 per a fail-safe script in the code, and gameplay will continue as if the fight had gone normally - with one exception, the highly powerful Eve will remain​ in your party. This is only doable on the Famicom release and its Virtual Console ports. Mother 1+2 on the GBA, plus the US prototype of this game and its Virtual Console analogue removed the glitch.