So the
The players are level 1
We have
Oracle
Bard
Rogue
Barbarian
Ranger
Alchemist
In the party. I don't know if all players will be there or not next time. But I would think a minimum of 4.
It's not necessarily boring. I ran this and the skeletons killed one of the characters. They were a rogue, ranger, sorcerer and cleric. If the party is having an easy time of it, add a couple more blood skeletons. They're pretty nasty as it is an they fit the story of the adventure.
With six players instead of four (the design cut-off for most modules), you do want to increase the difficulty a bit. Giving all the skeletons the advanced template would work; so would adding a couple more. But you sound like you don't just want more of the same thing. So switch things up a little.
Make a couple of different things into skeletons (dog skeletons, maybe a big bear skeleton) -- if the oracle channels positive energy, the skeletons will be pretty easy to take down, plus a barbarian ought to make mincemeat of them. Too many skeletons and the front-line PC will get swarmed under.
Maybe have an undead bard skeleton in the back, doing a xylophone imitation on its ribs -- if the PCs can take it down the others will be less effective. Give them a tactical objective that isn't just another monster.
Or have a couple more bloody skeletons hiding somewhere to the flanks and come out to engage the rear PCs after the frontline ones are engaged.
Also note: if the PCs just kill all the skeletons and go past them, in an hour they'll be back, and if the PCs aren't out of the tomb by then they may have another fight on their hands, and if they're badly wounded it could be lethal... part of the point of bloody skeletons is that you have to deal permanently with them. Can the PCs make the Knowledge (religion) checks to figure this out? Do they have holy water, or a bless spell, or positive energy channelling to permanently put the things down?
Chuck mount.
in the first rum, they fight against 6 normal skeletons. The difference between normal and bloody. is fast healing 1 and 2 extra hp and fort save. Also +4 channel resistance. if a skeleton survives for 3 turns that is unlikely. They would have 4hp more than a normal skeleton and I don't think the fort save will matter at all. So I think the 1st fight is more dangerous.
Tonyz
I like the bard idea. Giving them +1 attack and damage.
Edit. the skeleton template changes creatures cha to 10. So the bard would not have good spell dc and a few bard rounds. Is there a different undead template that do not change cha?
Would skeleton Champion Be a good one? I do not change the Cha. but +1 Cr on the creature.
Edit. bloody skeleton has 14 cha. I missed that.
The bard and Oracle have cure light wounds. That is positive energy that should destroy them.'
Also, should I use the broken simitars in the first room to make it easier and the claws in the last rum to make it harder?
The scimitar +0 1d6+0 damage is a lot worse than claw +2 1d4+2?
The bard is there to play music, not to cast spells. You could give it CHA 11 if you wanted to (you're the GM, monsters are what you say they are), but it could still cast cantrips with CHA 10.
One broken scimitar is a bit worse than 1 claw, but much worse than 2 claws ;). Skeletons of course are mindless and don't know it. You could see how the early encounter works and if it's too easy move to claws in the second.
Scimitar threatens!
Claws also do that. the draw back of claws is a 20*2 crit instead of 18-20*2. But I think that is worse than 2 attacks with more damage and better accuracy.
Did your group rest and recuperate? If they go, non-stop, through the adventure like my group did, that fight with the blood skeletons is more dangerous because, at that point, they're hurtin' from all the encounters leading up to that. Like I said, my group lost one character. The first fight was easier because they used a channel right off the bat. If you're looking to beef it up, just make sure you don't do it so much that you kill any of them, unless that's what you're going for. If you're looking for variety, tonyz has some good ideas. You could even wait to see if the group is having it too easy and have a couple blood skeletons climb down the pillars as reinforcements. Have blood drip on one of casters in the back, right before they scurry down all creepy-like to attack. That way, if it turns out that 4 is actually hard enough, you don't already have too many out and attacking.