The Windhovers' Call

Ozum will charge forward and attempt to strike one of the wights with his staff.

Shillelagh: 19 to hit wight 4, 6 bludgeoning damage

In a desperate attempt to keep the city guard alive, he will call out to a fallen guard.

Healing word: 6 healing to guard D (if possible)  

Kurt continues his attack one the Wight in front of him(3).

1st:Attack: 22 Damage: 11

2nd:Attack: 15 Damage: 7

Bonus Action:

off-hand::Attack: 12 Damage: 9

OOC= if Wight dies before attacks are through will move towards attacking Skeleton(3)

Xellos makes it to the Bridge and is alarmed (yet excited) at the  number of undead breaking through. He takes out a pinch of sulfur and bat guano, then starts a giant fireball materializes over his head. "Pain packer!" he yells as he throws it.

Metamagic: Quickened Spell (2pts) - Spell that takes 1 action only takes 1 bonus action.

Bonus action

Fireball Fire dmg: 26 (DEX ST DC 17 for half) 20ft radius

He would center it near Wight #5 & Skeleton #10, so it not only hits them, but also

Wights #6 & #7 and Skeletons #3, #4, #5, #8 (20ft radius - 8 targets)

He's basically trying to hit as many enemies as possible in the back while trying to not to hit the Guards.

Action

Xellos quickly takes out 3 nut shells and casts Confusion just to the right of Skeleton #6 and above Wight #4 so it can also hit Skeleton #2 & #5 (10ft sphere - 4 targets)

Wis ST 17 (refer to d10 table for possible actions for failures)

Kurt slashes the wight twice more; the off-hand strike proves to be the fatal blow. Wight 3 staggers to the left and crumples to the ground.

Ozum's attempt to strike the wight is unsuccessful. The fallen guard (D), however, is revived and begins to crawl away from the battle.

DEX saving throws for Xellos' fireball:

• Wight 5 (-2 on save due to slow spell): 13 (37 hp fire damage)
• Wight 6: 12 (37 hp fire damage)
• Wight 7 (-2 on save also):  8 (37 hp fire damage)
• Skeleton 3: 18 (destroyed)
• Skeleton 4: 6 (destroyed)
• Skeleton 5: 3 (destroyed)
• Skeleton 8: 4 (destroyed, despite making the saving throw)
• Skeleton 10: 17 (destroyed)

Effects of Xellos' confusion:

• Wight 4: 11 
• Skeleton 2: 2 
• Skeleton 5: 3 (irrelevant; the fireball made sure he would never be confused again)
• Skeleton 6: 12

NOTE: Confused behavior will be determined at the beginning of their turn.

Arissa's turn is next, followed by Kempis' and Bharash's (and the Chancellor's)

NOTE: Five wights remain (1, 4, 5, 6, and 7) and three skeletons remain (2, 6, and 7); see map below

Xellos remembers the Chancellor is not a warrior and says to him, "Aim for the skeletons on the left side, Chancellor. The big wights are resistant to non-magical attacks."

Kurt moves from the Fallen Wight to the Next Wight(5) right behind the fallen one.

1st:Attack: 29 Damage: 13

2nd:Attack: 10 Damage: 12

Bonus Action

Attack: 12 Damage: 9

The eagle swoops down again towards the wight who was injured by the spell (6) again and the elf archer fire at him again, hoping to him down. 

OOC: Are these turns for after Arissa and the NPCs?

(Kurt and Frandal did jump the gun just a bit. So, I will chronologically "insert" the attacks of the Chancellor, Bharash, and Kempis, followed by the actions of the undead."

 The Chancellor takes nervous aim at the nearest skeleton archer on the left side of the bridge: Attack: 4 Damage: 1

Kempis continues his barrage of attacks on the first wight: 

• Attack: 18 Damage: 7
• Attack: 28 Damage: 13
• Attack: 15 Damage: 9

From Bharash you see the familiar glow of several magic missile darts which separate in two groups as they fly toward the bridge. Wight 7 sustains 10 force damage; wight 6 sustains 15force damage. (These two damage numbers should be 14 and 18, respectively. I incorrectly entered the damage modifier). 

 For the undead, the following are subject to the effect of Xellos' confusion:

• Wight 4 (4): Creature attacks, randomly, a creature within range (guard A is its target)
• Skeleton 2 (3): Creature uses all of its movement randomly (skeleton moves directly left and tumbles off bridge)
• Skeleton 6(9): Creature behaves normally (fires an arrow at guard D)

The net effect of all attacks by the undead this round are as follows: 

• Kempis takes minor slashing damage from wight 1
• Guard A is killed after being slashed by wight 4 and taking an arrow from skeleton 7
• Guard G takes minor slashing damage from wight 6

Xellos exclaims, "Ha! Into the water with you!"

(Is Skeleton 6 attempting to swim? lol)

Round 3

Kurt: You successfully slash the wight three times, severely injuring it. 

Frandal: Two successful ranged attacks finish of wight 6; it collapses to the ground

Ozum, Arissa, and Xellos: Your turns are next (keep in mind that skeleton 2 and wight 6 have been dispatched)

Arissa runs up to Kurt and grants him protection from evil and good.

Seeing that his Confusion took effect and Wight #4 & Skeleton #6 are still under its influence, Xellos keeps pouring on the magic while keeping his concentration spell up!

Metamagic, Quickened Spell - 2pts

Action

He hurls another Fireball at the two remaining wights in the rear Wight #5 & #7

Fire dmg: 35 (DEX ST 17 for half)

Bonus Action

"Eat my magic missile!" He does three pelvic thrusts, and 3 magic darts fire from his body @ Wight #1!

Magic Missile force dmg: 11

Wight #4 & Skeleton #6 must make another WIS ST 17 on their turn to break Confusion. If not, they must take new actions from the d8 table.

Ozum runs to hit wight 4 and similarly revives guard A beneath his feet as he revived the previous guard.

Shillelagh: 25 to hit, 11 damage

Healing word: 7

Any undead who attack Kurt, who is currently under the effect of Arissa's protection spell, will do so at disadvantage. 

Xellos' fireball engulfs the rear-most wights in flame...

• DEX save for wight 5 (still under the effect of Ozum's slow spell): 7 (21 hp fire damage; wight destroyed)
• DEX save for wight 7 (also under the effect of Ozum's slow spell): 19 (21 hp fire damage; wight destroyed)

Ozum's melee attack against the wight is unsuccessful but the healing spell returns another guard to the land of the living. The guard coughs, gasps for some air, and begins, weakly, to stand. 

Everyone: After a few rounds of silence, Sariel's voice suddenly returns to the telepathic conversation you've been able to hold since leaving the Chancellor's house. "There is some new evil here! Through the north gate have come two large bear-like creatures. With burning eyes and flaming mouths..." She again goes silent. 

(Attack: 11 Damage: 14)Kempis brings down wight 1 with another swing of his axe, and the Chancellor lets loose another crossbow bolt, this time at skeleton 7 (Attack: 3 Damage: 4)

Bharash speaks telepathically. "The undead have little hope of keeping this bridge, my friends. You have fought well! Continue to do so while I pursue this new trouble described by Sariel." The wizard then flies northward into the darkness.

For the undead, turn 3, plays out as follows:

•  Wight 4 (save against confusion): 18 (spell broken)
• Skeleton 6 (save against confusion): 7 (spell remains in effect and creature (7) responds by becoming completely inert, doing  nothing this turn. 

Wight 4 and skeleton 7, make a desperate attempt to attack Kurt:

• Two sword attacks:Attack: 13 Damage: 5| Attack: 11 Damage: 6
• One ranged attack: Attack: 21 Damage: 4

EDIT: I failed to have the undead attack with disadvantage; so, here's the second roll for each. 

• Two sword attacks:Attack: 19 Damage: 9| Attack: 7 Damage: 3
• One ranged attack: Attack: 18 Damage: 3

All attacks against Kurt are unsuccessful.

Not having much success with the wight, Ozum shifts while still engaged with the undead to strike at skeleton 6.

Shillelagh: 15 to hit, 11 bludgeoning damage

Round 4

(NOTE: The confused skeleton that tumbled off the bridge attempted to swim upstream for a while but was eventually swept along with the current...)

Ozum: The skeleton crumples to the ground after you bludgeon it, shattering many of its ribs. 

Everyone: Only one skeleton and one wight remains. The two badly wounded guards have retreated from the bridge, heading southward. One of the guards remains locked in combat with wight 4, next to Kurt. Another guard has drawn his sword on the remaining skeleton. The last two remaining guards advance to the north end of the bridge under Kempis' command, seeking to hold their ground and hoping that this was the only siege on the bridge. Kempis' barks, "We stand firm here until further notice!"  (See updated map below). 

You then hear Kempis, telepathically: "Bharash...Sariel...Silverthread Bridge is nearly secure. Waiting for your instructions..." 

Arissa, Frandal, Kurt, and Xellos: Your actions are next, in any order. 

Moving to assist the beleaguered guard, Kurt engages it.

1st:Attack: 22 Damage: 8

2nd:Attack: 28 Damage: 12

Bonus:

off-hand:Attack: 14 Damage: 11

Xellos points his finger at the Wight and casts Fire bolt

Attack: 19 Damage: 17

Frandal fires two more arrows towards the remaining skeleton.