Well... i got one Ada from the first map, one from second to last, and i can only 2* the very last map, yes i know it's an extra and it doesn't even drop Ada, but that extra SC could be handy i mean, it's worth 4 slots for units

Now out of stamina but will only farm the last map that gives Ada, since it gives both the silver elf soldier i want to min cost and the archer that rises Spica's skill along with having the highest chance of dropping Ada ofc