The incorpoeral form of the figure swishes around the hammer taking no damage. 
The palanquin start to reverberate with an unholy wailing noise. 
Argetlam runs forward and tries to finish off the injured sentries. But is only able to strike one of them, collapsing it back into death with a flash of radiant damage. 

The surviving sentries turn on him and lash out with their spears, but Argetlam deftly parries the shafts with his shield. 

Disturbed by the wailing coming from the palanquin, Sheridan casts Create Bonfire right next to it and ducks behind a tree. 

The fire catches the palanquin alight, the wailing from inside increases in volume and the two ogre skeletons carrying it are scorched as they drop the palanquin. 

Taking the burnt handles of the palanquin the skeletons advance swinging at Draskan with them. The third ogre sleleton puts the chest down and does the same towards Argetlam. 
Argetlam takes a strike across the shoulders (11 damage) Draskan dodges one strike but is clobbered by the second (nat 20) for 25 damage

Reacting to the attack on Argetlam, Draskan lashes out at the Skeleton

The hammer smashes into the skeleton doing more damage than you thought it would, the skeleton staggers but remains upright

Oriki, seeing that the cloaked figure took no damage, peeps out of the undergrowth and shoots at the skeleton before ducking down and crawling to a new bush.

The bolt takes the most damaged skeleton through the jaw, shattering bone and severing whatever foul magic was animating the creature. Oriki slips through the shadows appearing to go unnoticed. 

Badly damaged the cloaked figure screeches and casts fear hitting everyone within its radius. 
DC 13 Wis save or become frightened of it

Argetlam is unaffected by its spell

Not affected by the spell, Draskan retaliates at the Skeleton attacking him

The ogre skeleton explodes into bonedust

Obliterating the first, Draskan turns his attention to the second Skeleton

The second one goes down under the tremendous blunt force trauma. 

From within the burning wreckage of the palanquin a floating figure emerges, undead flesh smouldering from the flames it spends its turn floating across the battlefield towards Sheridan.  

Argetlam swings at the humanoid and ogre skeleton bearing down at him,  channeling divine energy into his second strike to increase the damage against the sturdier ogre skeleton after the humanoid one falls

Sheridan backs away from the burning figure and tries to fire off an eldritch blast 

The soul of the guard swirls around Sheridan as he fires the blast, causing it to go wide, but whispering possible insights about the near future

The remaining ogre skeleton slams its club into Argetlam, forcing him to drop to a knee. 

Oriki shudders at the ghostly scream, and feels a rising dread in the pit of his stomach. Too scared to move, he puts his crossbow up over the bush, fires in the direction of the nearest ogre and wriggles away into the undergrowth