This is the most tedious achievement in the game and can take up a long time when clearing locations normally. So let me tell you how I did it, and how you can use this to easily beat the grind. As a bonus this also gets you lots of Vengeful Souls to complete the achievement to learn all spells!

This location is quite small and spawns a bunch of enemies close together and right after the level border. By repeatedly clearing them this racks up a lot of kills in no time. To reach this location quickly you can teleport to the Forest Sanctuary and head west until you reach the South Freshwater Swamp.



You'll enter the location from the North, through the West Freshwater Swamp. After that simply follow these steps:

1: Enter and walk a few steps in as the enemies spawn.
2: Cast your favourite AOE spell.
3: Finish up the stragglers and recharge mana at the same time.
4: Grab the loot and exit North.

This only takes a few seconds per rotation, so you can do it many times. By doing this method I got the achievement in about 7 in-game days from 08:00-23:00, and around an hour in real time. Now this is still tedious and not very engaging so if you wait until after you beat the game it'll still be a grind.

Instead try to take a day here and there to just farm this location for a day. You can easily fit this in while waiting for your crops to grow, rather than just sleeping the day away. The loot here is also decent, I brought back up to 20K Paw Pennies for a day.



All enemies here also are aggressive, meaning they all have a chance to drop Vengeful Souls. You'll need a lot of these to get all spells unlocked so it is definitely worth doing this as early as you can handle the enemies comfortably!

Happy Grinding!