1 - The missing villagers of Tar

Malchuck won't be able to reach that position, as Vachel retreated in the bushes to the east (50ft from you). You can either move in that direction but end your turn halfway, or go to the bush north-west of your current position instead.
My bad, you both go in the same bush. I'll fix the map.

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The ground before Malchuck twists and sprouts hard spikes and thorns. Being very close to where the thing is happening, the spidery creatures seem to perceive the noise of leaves and twigs moving and they... shriek. They emit a disgusting, hissing and rumbling noise before charging toward what they spotted. Reacting to that call, the voices respond with two short orders:
તેઓએ કંઈક સાંભળ્યું, જાઓ! તેમની સાથે જાઓ!And those north of the camp see two more creatures dashing to join the group. Those are giant spiders, regular ones. You know how deadly they can be, especially because they can capture unsuspecting creatures in their webs and drag them back into their lairs.

... And you were right! My bad mistaking east and west when placing you.

Edit:

The southern group spidery-things (I call them spiderlings, so let's call them that) respond to the order, going from slow-search advance to fast movement. Approaching at great speed, they don't seem like they are looking for their targets and more like they already know where to go. They are about to pass right next to Zegar when...
... appearing suddenly on their left, an enormous fireball files right at them and catches one mid-hop, burns another one while the last one gets thrown against a rock by the sudden explosion, but manages to get by on its shaking legs. Two trees catch fire right behind them, and any lesser plant probably got burnt instantly. Zegar stands by, hidden in his bush, still ready to hit if the creature passes anywhere near him.

North of the camp, two of the incoming spiderlings shriek as their legs get slashed by hidden thorns and they try to jump forward to pass above them. One of them manages to jump only to land in more spikes while the second one misses the jump and ends up rolling in the dangerous area. The last creature, alerted by the the other ones, tries to go around the area but fails to discern its limits and gets hurt too before backing off.

Seeing the menacing light coming, the barely standing Spiderling does his best to avoid getting hit by it and takes a side step just in time to dodge the incoming attack.

With thorns and spikes up to its neck, the spiderling the just jumped forward into Malchuck trap doesn't see the attack or where it came from. But even if the arrow hits the intended target, it ricochets on his carapace without apparent damage.

Coming from the out of sight range, three giant spiders join the battle. The first one ends up in Malchuck's spikes and loses a leg in the process, but the two others adjust their trajectory and go around it. They are almost in the camp and seem to continue that way with purpose.
They are followed by two unidentified humanoids that would be best described as the result of a cross between a kobold and a spider.

Vachel, you're up!

Last round ended with your readied action being triggered. This is a new round, and it's your turn. Hope it helps to get things straight.

The magic bolt shot by Vachel hits it exactly where he was aiming : in one of the spiderling's glowing eyes. The creature blenches, shrieks of surprise and pain, and writhes in pain until it remains motionless on the ground.
The two others immediately charge their attacker. The first battles with the magical thorns and spikes, losing limb after limb until is fall down, slowly dying of exsanguination. The second one, going around the dangerous area, jump on Vachel as soon as it reaches him in an attempt to knock him prone, but Vachel holds his ground and dodges the creature's vicious attack.

After avoiding Cryst's attack, the remaining spiderling south of the camp dashes forward, trying to hide behind a bush and prepare some kind of counterattack... and alert to the slightest movement now that its life clearly is on the line, it dodges Zegar's surprise attack and freezes, probably aware of its own situation.