easy actually, of course, depends on how much money u want to put in the game and how OPed are your items.
Let's say you have an OP archer full of nice gears, put all these gears in a lv 1 char, then get it to lv 99 in a couple of hours may be less, then get in ACM and u will hit 101-102 in 1 hour; pay another hour and u will hit 102-103 probably, then go castilla 110, then u can go blazing and leave it auto hunt till next day.