Here we will talk about witch is the best pentagrams for each damage class (because supports are gonna use the optimal pentagrams for the area)
First of all, we will look into the Ruud skills and Skills Strenghtener (800+) as they are the main skills post level 400...
The Ruud skills for the Dark Knight is the Fire Blow, and the Skill Strenghtener at level 800 is also to this skill... So Fire Pentagram is a no brainer.
It has skill Strenghtener for Rageful Blow (earth) and Blow (wind) aswell... Not so good tho...
For the Dark Wizard you have 2 options... Earth (for 2 Ruud skills) or Dark (PVP and Ruud Skill)
For the Elf there is only one option... Wind Pentagram
Melee: Fire or Water (both Ruud) Pentagrams Dark for Debuff Skill (All have Strenghtener)
Energy: Dark (Better) or Earth Pentagrams (Both Ruud) or Wind (AoE) (All have Strenghtener)
Ruud Skill = Wind Pentagram -- No Brainer
Dark or Fire (Chaotic and Fire Burst) -- (Only with Strenghtener)
Fire or Water (both Ruud) Pentagrams
Wind (Only with Strenghtener)
Agility: Water Pentagrams
Strengh: Fire Pentagrams
Hybrid: Wind Pentagrams
Now you can check the best Pentagram combination for your party/character in the spreadsheet below