"If they can see us before we can see them, which I think is common in the Darklands, then it won't do any good to have some of our group hiding further back. So deception it is. Prisoner gambit? Play along and plan to attack as soon as we can see the Naga. Weapons sheathed for now. Hold your hands in front of you; we will wrap some rope loosely around them."
Benedict uses his Alter Self SLA to take the form of an Orc. "Kisegar, you bring up the rear to keep up the facade. Point your crossbow at William. Aerel, you can be with us or sneaking around behind cover."
Benedict will go first, with the others in between himself and Kisegar. He'll be holding the +1 Spear over his head in two hands, holding it not as a weapon but as a gift.
Haela will be right behind him (to share teamwork feats).
Grum and Amkarang will follow, so that Haela can Dimension Door all of the melee fighters at once if needed.
"I don't want to risk your lives by being seen too soon, so I will be behind you. What's the signal to move up? And a second signal to engage? To keep your options open."
"Probably Grum or me shouting Attack! - I can't say for sure how well this plan is going to work."
Aerel smiles, shakes his head, and fades from view.
Raises his hands and grins, "Variety is the spice of life, my friends. I will do my best to disappear until you call out."
A massive, snake-like body rises from the earth capped with a humanoid head sporting a mouth full of fangs. Even with much of its body still underground, its size is impressive.
"Wise you are to make an offering, but you will send them to me. Send them forward!"
The naga hisses at the battle cry, but the underground aberration was on high alert with the group of intruders in its domain.
Haela uses a swift action to share Shake it Off with the party (8 rounds), a move action to draw her axe, and then a standard action to activate Teleportation Mastery, bringing Grum, Benedict, and Amkarang into melee reach of the naga.
Everybody has Shake it Off; that is a +1 to all saves for Amkarang, William, and Aerel; +3 for Grum and Haela, and +2 for Benedict.
Kisegar fires off a shot from her crossbow.
The naga roars in surprise as the melee fighters are brought around it in the blink of an eye. It looks around at the foes around it, deciding at random to bite at Amkarang!
The naga then withdraws into the ground, the hole collapsing behind it!
Haela swings at the naga as it retreats.
"Aerel, William - move to us."
"You too, Kisegar."
"Let's keep moving together."
She heals Amkarang of all of his wounds.
Aerel hustles forward, curious what's occurred to change the plan.
Seeing his allies and no opponent, he searches for the dark naga, looking and listening.
William moves forward and casts haste on the group. "Be ready for it to come back up. We should spread out some so it doesn't get us all in a spell."
"We are better off closer together if it does cast a spell."
Benedict uses his Tactician ability to share Lastwall Phalanx - which, as a sacred bonus, stacks with Shake it Off (which is untyped).