Here are my builds for reference, I may one day decide to make a dedicated Combat Sage guild for them: Just a note that all these builds I generally do swap around and play with them when I am bored so I can validate they are all workable builds (my Sorc is base lvl 155 but job 60)
http://irowiki.org/~...drakDaNeBkD1In1
This build I make use of the insig ability to change mob attacks to an element and wear resist gears towards it with Extr Vac used to round up the mobs into the center of the insig, leaving me free to put my spirit at lvl 3 on passive mode to continue to barrage bolts after my SF runs out since the bolts pelted by your spirit is also effected by the double bolt skill.
http://irowiki.org/~...qkAkDaOeBkD1In1
This is my Squaddie Sorc with a twist. I cannot go into much detail with how it works but once again it makes use of resist gears of the element to resist the elemental insignia i place down, Extr Vac is the same job. The difference lies within the cards I put into the weapon and as you can notice, I make use of the lvl 3 spirits on attack mode to help dish out further damage as well as their inherant AoE skills, as well as having the manual command to make them use their skill since that does not run on the delays and cooldowns of the sorc him/herself. This is a crit build obviously but I can assure you it does well for AoE coverage, I think if you look closely you will see where the coverage is coming from.
http://irowiki.org/~...dlakDaNeBhc1In1
This is my specialized "Wind Mage" build which plays the most similarly to Negi from Negima. VS is an opening move after trapping the mobs in the Extr Vac and having all necessary placements as per usual. plays similar to the very first SF build except the emphasis is increasing the damage of wind element spells mostly with the incorporation of yjr VS AoE which has by far the relatively most low cooldown (and an aftercast delay which is shortened by 50% by wind insignia lvl 3, iROwiki says its water spells but VS seems to be effected by this so you be the judge), so its much more prefered you lay down water insig lvl 2 and Whirlwind on the ground to increase as much as possible.
Now for a much more special build I play rarely these days due to the intense lag but until last year was making people go wtf when i walk around in Scaraba hole lvl 2:
http://irowiki.org/~...saNkAgChneB3In1
This is my "walkerer" build which I have used up until late last year when the lag on the server was starting to get abit too hard to level around with, as you can see having even abit of lag forces this build to become very much invalid as a leveling build. If done correctly you can mob up pretty much an entire map, I personally had around 20-30 scaraba's chasing me with this build on. As you can note, Firewall, Safetywall and Fibre are there to give abit of breathing space between when you need to stop for SP recharging if you run low on supplies as this build basically means you never stop if at all unless the situation really calls for it, the walls and fibre also are helpful when redirecting yourself to avoid needless collisions with mobs so you can keep them behind you most times as you walk with the Fire/Lightning Walk. Extreme Vac is probably the best to use when you must stop for a grace period and if done correctly keeps the mobs taking damage from the Walk. I added the poison tree into the build but its entirely optional whether you use it or not. I personally havent much but every now and then using poison burst does give you abit of satisfaction. Notice Hocus pocus? I leave this at level 1 because I use this as an emergency lifeline, lvl1 is nearly around a 50% chance it does rejuvenate on you (which completely restores SP and HP) and maybe around 30% chance instant death (you just randomly die) but the odds are good I feel, use if you dare like I do!