The option to use your own blood for a sample if you are playing as a Dunmer, Altmer, Bosmer, or Orsimer.

Seeing as Dunmer and Altmer blood is hard to come by without murdering an NPC in town, that would make things a little easier and there's no good reason why an elven player's blood wouldn't be an option.

Using the spoiler section is an idea

I came across plenty of Altmer necromancers and Dunmer bandits though.

Well the only way you get the blood is killing them, obviously. So maybe for some reason the blood is required to come out of a dead mer, or maybe it was just so you couldn't cut corners in the quest.

Well Septimus never said that you have to murder them before taking the blood. Arguably a sample could be taken from a living person if they were willing,

I found a necromancer dungeon, and he just so happened to have a bunch of corpses in there...and i got all 4 at once.

I second that.

Thirded

Forthed

Are people really this thick that they can't understand what a spoiler is or is it that they enjoy destroying others experiances?

Alot of bandit archers are bosmer and necromancers are altmer.

I tend to just assume people don't always think about it. I doubt many people are actively trying to spoil things. Most people just get a question in their head and post a thread about it before they think about the possibility of spoilers.