I have played DFO for several years, and I like to write guide for DFO. This is a brief guide for DFO Spitfires, Mechanics, Brawlers and Necromancer.

Mechanics - More bot summons, often find myself (80% of playing) spamming RX-78 Land Runner and EX-S Viper while Air Combat Mech draws half the attention. The G series burns way too much mp and the individual series are too short, often forget to change in hectic battle trying to avoid getting cornered. Without G series, Mechanic just feels like a a naked (exposed to enemy attacks) summoner, the entire time. Spawning a Auto-Runner summoning device (similar to Chaos's Hell Gate). A character sized (humanoid) tank with cannons on it's back dropped by Air Drop. Turning Air Drop into a continuous skill, dropping 1 -3 bots (randomly) periodically. Long range mortar support fire, similar to Spitfire's Neil the Sniper just antonymous with a duration.

Spitfires - Their supposed to be like commanders/strategist of armies, but both only summons troops for awakenings. More skills focused on commanding an army would be cool. Summon solider(s), of a list (similar to Chaos's Tech Tree) l who run in, from off screen, shooting (or other things) and then retreat. Spitfires knells down with a soldier holding a electric shield over them while control is switched to a soldier who runs in off screen and fights till killed or runs out of it's own set of mana DFO gold. Other skills that have Spitfires feel like they are commanding an army, maybe give this one the long range mortar support fire.

Nen Masters - They always felt, lacking, to me. A cross between Asura's and Strikers. While Asura projects inner power, she could utilize the exterior (Nen) in the surrounding area (map) and manipulate it both up close and afar. Creating a stationary AoE, maybe in the form of a ball, in front of the Nen that pulls enemies to the center while damaging them. Using Doppelgangers to buy DFO gold, execute skills and having the explosion stun. Having the awakening act on it's own over a period of time, healing allies, and then exploding at the end. Exploding Nen around the area. Control the Nen without enemies to manipulate them into fighting for your cheap DFO gold.

Brawlers - Making the Female Brawler's Awakening auto-explode, trying to count the duration, 9 seconds if I remember right, is difficult in combat, I often just explode it 2-3 seconds in to avoid wasting it.

Necromancer - I want to see Nicholas Sister (forget her name) as a summon, maybe interchangeable and changing Nicholas' active skills when she's in use. Another ghost besides Vallacre The Slaughterer with interchangeable skills for the other ghost. Removal of their first awakening for something else, it's just suicidal against bosses and mini-bosses, the sub-class is already a suicidal with the skill converting HP into int for a short time, very pot heavy on both HP and MP. More skills manipulating physical manifestations of the dead besides Vallacre and Zombies (which Nicholas summons). Maybe Necromancer summons other servants of Vallacre or a death god (that Vallacre either tames or is in service too). Removal of Vallacre MP cost for attacks, don't understand why basic attacks cost mp, makes him mostly useful for the buff, the grouping with Dance and Guillotine (which has a good damage output for the time being) are his only good active uses the way I see it. Giving Nicholas more basic skills or rework them so that he isn't always positioning enemies out of range of his Aracodas (forget the name) drop, maybe as passives through the levels. The Necromancer feels like a support to Nicholas most of the time, I'd like to see them have a more active role.