Erlan 

I will suggest tracking for now. We can stay far enough back not to alert them. We could always ambush them later if need be. And maybe if it comes to it, might be easier to kill them in their lair rather than the woods where they can run. 

Re-roll survival with +3 bonus for guidance.

Erlan

Survival: 19 

Ranger carefully leads the party though the woods, his elven vision allows him to see subtle signs of beasts passing even in the dark of night. Druid walks not far behind, staff at the ready. Crassus does his best to follow their example, but it's becoming more and more difficult for a large and heavy warrior. Violet resists the urge to light the way, knowing it can and will draw unwanted attention, but the darkness is unnerving. At least the voices have quited just enough that she cannot hear them. Sorceress normally appreciates their input (most of the time), but sometimes they do grow tiresome.

They go farther and farther into the Witchwood, but nothing happens. The creature has kept her word so far - they walk undisturbed by the forest dwellers.

Suddenly, when everyone was almost sure they will find nothing, Ranger hears movement in the tall bushes. The  noise intensifies and is then gone for a moment. The next time the group can hear it, it comes from behind them, leaving two people looking back and the rest continuing to stare forward.

Before anyone can do anything, a huge mangy beast springs from behind the first bush and a smaller one - from behind the second. To say they're unusually large would be a monumental understatement. They're huge. The largest of jackalweres are normally thigh-high, the two of these easily reach a human waist. An unsettling growl is coming from both. They are clearly not into diplomacy...

Combat time. Okay, layout of the field: The group is in the clearing, 5 feet away from each other, surrounded by two large jackalweres. Tree line is 10 feet away from either shapechanger.

General rules here:

1. We roll for initiative ONCE in the beginning of every battle and that determines the order of actions for the rest of the encounter.

2. You can roll saving throws for creatures you attack if you look up all math required to save the time, but only I describe the result of the rolls, particularly critical failures and succeses.

3. Consider each shapechanger a standard Jackalwere, but I did not say they were large for no reason. They have CR of 1, double of the standard HP and double the attack. AC is 16. STR 14 DEX 16 CON 13. Everything else is the same.

4. As of now, no weapons you own can damage them, so after you roll for initiative (first round), you must take an action to apply the silverwater, unless you'd rather fight with magic.

Jacklarweres initiative roll: 10

Crassus Initiative: 21 (Natural 20+1)

Crassus will unleash his breath weapon at  the jackalweres, the DC is 12. I rolled their saves, the first one failed with a 7, second one made it with a 15. The breath attack dealt 9 points of damage to the one who failed its save and 4 to the one who succeeded.

Crassus will then burn his Action Surge to apply the silverwater.

If I remember correctly, breath weapon goes out in a cone, not a sphere, and they are at the opposite sides from you. That means you can only hit one jackalwere per breath. So you've hit the one enemy closer to you, dealing him 9 poins of damage. Also, your breath weapon os lightning, right? Just in case it comes up again.

That's correct. The breath weapon deals lightning damage. I should've read better when I fired my breath weapon, because I didn't realize where the jackalweres were positioned.

 Initiative: 8

Pict is taken aback for a moment by the sudden appearance of the Jackalweres and their unusual size. He takes a moment too long to formulate a plan of action before they move.

Violet is also taken aback by the sudden ambush of these enormous creatures. For the moment she seems overstrained by the situation.

Erlan 

Initiative: 15

The lighting breath of a dragonborn got the jackalwere angry. Or, to be more precise, angrier. But shapechangers are not creatures to be trifled with.

The first one, with fur charred by lighting, launches an attack at the warrior. It jumps forard, baring its teeth.

Jackalwere1 (27 HP) attack - 7, damage - 9, Crassus AC is 16, if attack equals or exceeds it, he's hit. If not, jackalwere runs right past him, ending up in the middle of a circle you've formed.

It's packmate is not as eager to jump into action, however. It lets out a low, but melodic growl and stares right into the eyes of the sorceress. The gaze is hypnotic. As if under a spell, her eyelids grow heavier and heavier.

Jackalwere2 (36 HP) is using Sleep Gaze on Violet. You make wisdom saving throw against DC of ten (allow me): 10, if you succeed, you lose concentration and the spell you've prepared fail, but you stay awake. If you fail, the spell fails and you've been hypnotized into slumber for ten minutes or until someone uses their action to slap you awake.

Also, guys, remember that Erlan and Pict are inspired, that means they can roll with advantage, but be careful when you use it, the inspiration won't last. I'll give each two actions you can take while inspired.

Order for the next turn will be:

1.Crassus

2. Violet

3. Jackalweres

4. Pict and Erlan act simultaniously (the two of you are left for this turn)

Crassus is going to take the hit, but if the jackalwere is running past him, that should provoke an Attack of Opportunity.

Attack: 18

Damage: 8

Erlan

with inspiration I will remove the liquid given by the dryad and coat my dagger in the liquid. I will rush and attack jackelwere1. Seems to me jackelwere2 is the leader and may be reasoned with after one is closer to death. I lung at the jackelwere with my blade. 

Attack: 20 Attack w/ advantage: 12 Damage:7 

Pict, having finally collected himself, focuses his efforts on Jackalwere 1.

He slides his hand down the length of his quarterstaff while whispering words of power, casting shillelagh as a bonus action, and causing a light magical sheen to cover the gnarled wood. He then moves within reach of Crassus and Erlan, and gathers more of his magical power into his staff, raising it in the air and casting entangle, centering the spell behind the Jackalwere while carefully avoiding catching his allies in the radius. The roots from nearby plants and trees that run underneath the ground in the clearing begin to dig upwards through the earth, grasping out at the legs of the Jackalwere.

Jackalwere 1 DC 13 Strength Saving Throw: 13

That should take it back to Crassus, who will move so that he and Erlan are flanking Jackalwere 1, if they aren't already. Then he'll attack with his greatsword again.

Attack (with advantage): 11

Violet will stare into the eyes of the Jackalwere.

Math so far:

Crassus - 12

Violet, Pict and Erlan have not yet taken any damage. Pict and Erlan can take 1 more action with advantage until inspiration ends,

Violet is still sleeping.

Jackalwere1, the one near Crassus has 27 HP (Crassus, you rolled for attack, but not for damage. It doesn't matter right now, their AC is higher that that roll, but I'll remind just in case. Also, the enemy did bite you, so no attack of opportunity, it would've happened only if it missed, in that case, the jack would've run past you. It didn't.) The movement of jackalwere1 is slowed as if moving through difficult terrain, but is is not restrained.

Jackalwere2, the one Erlan attacked, has 29 HP right now.

The jackalweres continue their attack. The one closer to Crassus whines as the roots and vines that have sprung from the earth attempt to bind its paws, but persists still. Its black eyes filled with rage, creature launches another attack against the fighter.

Jackalwere1 attack roll: 6

Jackawere1 damage roll: 10

If it misses, there's an attack of opportunity for the fighter. If it doesn't, well, tough luck.

It the meantime, it's packmate concentrates on the Ranger, having succesfully put Violet to sleep.

Jackalwere2 attack: 17

Jackalwere2 damage: 7

Same deal here, attackof opportunity if the jack2 misses, no attack of opportunity if it hits.

Also, on the sidenote. Your ability to negotiate with beasts (if you still want to) will depend on which one drops to 0 HP first. I am not telling you which one.

Just in case, yes, the jack1 attack failed, Crassus has the attack of opportunity.

Jack2 attack succeeds, critically. So the jack2 bithes Erlan in the crotch (sorry, Erlan), causing a lot of pain and anger. And 6 points of damage to boot.

Violet will awaken after one MORE turn, unless someone decides that her magic will be of use earlier.