Turned in Bandit Sashes as Human Necro in Qeynos
 

Now my guild masters are KoS. Am I screwed?

The faction you lowered (I believe) is https://wiki.project1999.com/Bloodsabers.

If you look at that page you'll see a list of quests you can do (although many might be a challenge with your faction at KoS) and mobs you can kill to fix the faction. The latter seems like your better recovery path: you can look through the mobs listed to figure out what to kill, but if nothing else you can just kill that koalindl fish over and over until your faction recovers :)

might not be financially feasible but giving 5gp repeatedly to guard shilster in nk is one the least negatively impactful ways to repair bloodsaber faction.

How many turn ins would this take to get from scowl to apprehensive?

Bloodsabers, do the tacklebox quest. Then turn in the tunic to firepride. Do that a bunch!

ah you went to scowling? a shit ton.........
another option, depending on your other faction levels would be to do the tacklebox quest then go turn in the dress, can be done in same zone and nets all positive factions.
https://wiki.project1999.com/Faren%27s_Tacklebox
https://wiki.project1999.com/Hurrieta%27s_Tunic_Quest


just the first part of the tunic quest though.
disclaimer: my experience is on blue so not sure if these quests available on green.

Each run will net you +3 bloodsaber
giving to shilster is only +1pt but can be done quicker, though more expensive
charts for each level of /con are shown here, put your running shoes on :)
https://wiki.project1999.com/Faction

Just one quick note: you may be basing that on actual data, in which case ignore the rest ... but if you're basing that on the wiki please don't.

While the wiki is 99% accurate on which factions a quest/mob gives, the specific numbers it has are way off. They were copied from some incorrect live source when the wiki was created, and if there was an easy way to mass remove them I would, because they're wrong more often than not and only confuse people.

Trust the wiki on factions, but please don't rely on the specific numbers. Assume every faction hit gives +1 or -1 until you see evidence otherwise, if you don't want to be disappointed by how long your faction grind takes.

the numbers I got originally from zam and verified with personal experience, I have done a ton of factioning on my lizard necro.

The first part of that statement scared me (to anyone reading this: please don't trust zam for anything, as the game has changed a ton since 2001) ... but the second part made me :)

In-game data > all.