You don't need to dodge, just keep moving and you should rarely get hit. Staying high may help.
The memory eaters tend to stay near the nest area, so you can keep heading back to the waterfall, clear out any wandering around or that followed you, and head back towards the nests to target some more.
Shoot off a Fire Sphere every time the cooldown time is up and you will kill them faster than the nests can spit them out. You don't need to rush to get a target immediately after the cooldown time, but it should only take a couple seconds anyway if you are flying around the nests, or about 5 seconds if you are near the waterfall and have to go find one.
