I am a level 59 character from server Beiyi who has consistently been grinding maps at PK spots. Even though it is mentally exhausting and time-consuming, I find joy in it. Recently, in preparation for reaching level 60 and preparing for Terra, I researched optimal maps for Light and Dark grinding. Based on my habits, I've devised a strategy and, during the maintenance period, I'd like to share it with everyone, hoping to spark some useful discussions.
Passives: Full levels in Mobile Casting, Magic Memorization, Light Mastery, and Dark Mastery. Fire Mastery and Ice Mastery both at level 2.
Actives: Level 5 Jack Bomb, Level 5 Frost Snowman, Level 20 Lightning Ball, Level 20 Black Cat.
Fire Bolt at level 10 (I used to use level 20 Fire in PK matches, and level 1 Fire doesn't suit me well in terms of damage and range, so I leveled it up to 10).
Black Ball at level 5.
Ice Wall at level 15 (For maps like Ruins, Mechanical Cows, and Bugs where enemies have high HP and deal significant damage, an Ice Wall that slows them down can save you a lot of time, especially when soloing. The reason I didn't max it out is due to SP limitations...).
Raiwen at level 1.