The first AoE you get it Ground Boom. It has a one minute timer, so you can't really AoE with it unless you've got 984755 Str and Ground Boom one hit kills everything.
The next one you get is Silence Blow Lv2 at Lv30. By Lv37, you have a lot more AoEs and grinding gets better. The AoEs still have long recharge times and most likely, not everything will be dead after them. At Lv37, you also get Demon Hushing which is useful for finishing off the last few mobs.
If you're grinding with a battle build, I would suggest to always have strong element in your weapon. Without that, a HM battle build is probably less effective in AoE than a NM Fighter/Warrior.
Other than that, it would be similar to the tank build. Round up the mobs and kill them all with your AoEs. Craft and Life Lapis are always my favorites for DPS class grinding.