14 points of radiant damage each.  Spider 6 attacks Jalt:

Attack: 6 Damage: 8

Spider 7 attacks Tangle:

Attack: 25 Damage: 9

That's 9 points of piercing damage from the spider's bite - reduced by reaction, I assume?  Tangle should also make a CON save, DC11, taking 7 poison damage on a fail, half on a success.

Jalt is up.

Tangle’s Con Save vs DC 11: 10 

Tangle twists uncannily, taking only a glancing blow from the spider, but the venom hits her hard. (18 damage, total, yes?)

Yes.

Jalt swings at Ettercap 3 with the Staff of Healing Attack: 16 Damage: 5  and with War priest swings again Attack: 7 Damage: 5

Jalt's first blow takes down Ettercap 3, so I assume the second blow transfers to Spider 6.

Several spiders move into, or start their turn in, Jalt's Spirit Guardians so give me a fresh damage roll please.

SG: 15

Spider 4 WIS save: 17

Spider 4 gets dragon-nibbled, but not too badly.

Spider 3 attacks Soar:
Bite Attack: 12 Damage: 10

Spider 4 attacks Tangle:
Bite Attack: 16 Damage: 9

That's a pair of misses.

Spiders 5, 1 and 2 surround and assault Bazavur:
Bite Attack: 15 Damage: 5
Bite Attack: 21 Damage: 9
Bite Attack: 20 Damage: 6

Spider 5 alone hits, so Bazavur makes his CON save against poison: 25

And he succeeds, taking half of 7 poison damage.

Round Three
Tangle and Bazavur
Soar
Ettercaps
Spiders 6 and 7
Jalt
Spiders 3, 4 and 5
Spiders 1 and 2

Tangle and Bazavur are up.

Tangle spares a quick glance north at Bazavur, but has problems of her own right now. She slashes in at the spider before her.

Move: no, for Steady Aim
Bonus Action: Steady Aim for Adv
Action: stab Spider 7 with Adv and thus Sneak: 21 to hit, for 25 

Reaction: reserved for Uncanny Dodge 

Tangle slices Spider 7 into two grotesque pieces. Spider 7 is dead.

Bazavur will rage, and take the Dodge action, holding off the spiders around him until you can finish the others and come to his aid.

Soar is up.

"Oh fer-everlov- Bazavur! Remember we talked abou- argh" Soar barks through gritted teeth as she does her best to slice up Spider 3.

Attack: 27 Damage: 11
Extra Attack: 24 Damage: 11

If it drops she moves to flank Spider 1 with Bazavur.

Soar slashes and slashes at Spider 3 - doing a lot of damage, but not quite bringing it down.

(I've removed Ettercap 3 from the map, as it was dead.)

Ettercap 1 attacks Bazavur:
Bite Attack: 9 Damage: 8
Claw Attack: 20 Damage: 5

Ettercap 2 moves in to attack Soar
WIS save for Jalt's spell: 14

Bite Attack: 15 Damage: 4
Claw: Attack: 19 Damage: 9

Ettercap 2 takes 15 points of damage, and deals out 0 points of damage.

Spider 6 WIS save: 2

Attacks against Jalt:
Attack: 18 Damage: 9
Attack: 24 Damage: 12

Spider 6 doesn't even get to make its attacks: it is ripped to shreds by flying dragons.

Jalt is up.