You might want to go to Vultures and do a mini-burst. Choose the Wind-Element ones. ( You can also train Roca here and yes, she won't die ) However, I am seemingly- sure she will die if you train her at Water-Element Vulture. And, she won't die at AFK-train if you 1-HIT K.O it and you must have the Food Supply part enabled by the way. It hits my Roca for about 150++ at level 25. At level 25, she should have
300++ HP so it's fine. However I still suggest you to test the damage Vultures do on her FIRST. (I recommend this for (A) and not recommended for (B)) -