Thing's you will need "azzy's ai controller found here http://iro.ragnarokonline.com/forum/forums/thread-view.asp?tid=32534&posts=162&start=1
Open the folder,go to the ai control click azzy ai/what you named it go to merc tab,click default tactic and set it to as follow's
basic behavior/ attack high
Ok so you all have seen the out dated guide's of wiki for iro and the have finshed guide's guides on the main forum's telling you places and where would be best to level. This is a guide "to Ymir only" on how to power level most any account.
Start on noob island "if your just starting" by doing all the little quest there. Talk to everyone,you should be at base 8 or higher before you leave.
From the very start of thing's buy a few spear merc's at level 15. They are very cheap and can easily be obtained buy farming garbage or asking for a small loan from a guild member.
2. once you have your spear merc's "at least 10" "located in pontera to left" enter the building and talk to the recruiter,agree to help and you will be telly-ed to pont Culvert.
3. click on the merc scroll and then enter the culvert,only a hand full of thing are agressive here.
4. walk around the map stopping only long enough to attack/let you merc kill a mob.
5. at level 25,go buy 10 level 2 spear merc's and head for floor's 2-3 "carry potions with you at this time as there are aggro mobs here"
6.after you are done with your 10 level 2 merc's you should be around level 40-45 "make sure at job 10 you change to your desired job class"
7.at level 55 move your self to payon "pont warp to payon and save.
8. walk up to archer village,that to the top right side of payon.
9 take the second left to the bowman merc guild and buy 10 level 5 merc's.
10. walk back down to payon and out the right side of the map
11. walk over and out the bottom of this map
12.walk right out of this map
13. Now you should see doki's/greatest general's,spore's and nine tails "avoid the 9 tails buy useing fly wing's"
14.walk the map over and over picking up the doki horn's you and you merc just collected "keep them to sale or use them for the turn for quicker leveling"
this is by far the fastest/easiest/cheapest way i have found to level a character. I would say in 24 hours worth the game play you should hit the mid 60's and both job changes with ease
edit: due to changes or over sites im altering this guide to reflect the new/over looked merc levels.
Change's made "movement from pont to payon at 55 and merc grade 4 was changed to 5