I did a lot of test I will suggest story 2-2-8 (the royal bloodline) 1)8 enemies (any enemy has roughly 85%-90% of drop a chest) 2)Any chest has roughly 20% of cointain a faint memory 3)energy efficient cz u get 1,4 memory/6 rng Ps u need mediena one shot one row of 4 enemies and a friend mediena to one shot the other row of 4 enemies