Fairly certain Rogues can Disengage as a bonus action. So you could still take an action as well if you wanted.

Centurion strikes and slashes the gnoll across the chest, it yelps as it falls backwards over the edge of the tower, hurtling to it's death. A passerby orc with a satchel over his shoulder reaches out as it falls past, but decides that would be a bad idea and just watched the gnoll go past, looking up at the sound of battle overhead with confusion, then carrying on with his business.

4 gnolls left

Seeing Centurion's renewed vigor after his second wind, Elero will change direction and run north to help his other comrades, but will return fire with his crossbow at the hexed gnoll who shot at him.

To hit 14 and 9 damage

And that gnoll goes down too. Crossbow bolt to the neck.

Evelyn, Erix, and Kit up. With Mark still to take an action if he can/wants to.

I took a level in fighter instead of rogue so I can’t do that yet. But I will use my bonus action to second wind to heal 11

aha all good, i forgot that

Kit transfers his hex and looses another eldritch blast at the gnoll toppled from the tower. 

atk: 19 damage: 8 + 5 hex 

So Evelyn, Erix, and Kit up

The gnoll takes the eldritch blast straight to the face, still up, but has had a bad couple rounds. Looking very angry.

Evelyn and Erix up

With 2 gnolls closeby Erix casts Thunderwave, hoping to push one of them over the edge maybe and at least do some good damage.

DC14 Con save or take 3 thunder damage and be pushed back 10ft (half damage on succesful save)

If both are pushed back he'll also move away to put a bit more distance in between.

Gnoll Con Saves:

1: 9

2: 17

The gnoll closest to you is blown apart by the thunderwave. The other is able to avoid the full brunt of the spell but is hit by the parts of it's friend who was just exploded, taking a battering in the process. This one is looking real beat, while the one attack Centurion hasn't taken a hit yet.

Evelyn throws an Eldritch Blast at the one near Erix: 

Attack: 18 Damage: 10 Force Damage

And the blast goes wide, narrowly missing the beaten gnoll. The gnoll makes a running attack against Evelyn, while the other makes another stab at Centurion, not even realising the poor situation his comrades are in.:

Attack against Centurion: 19 Damage: 9 Piercing

Attack against Evelyn: 12 Damage: 8 Piercing

Y'all are up

Elero will use his 30' of movement to run to the opposite side of the gnoll engaged with Centurion, dropping his crossbow and drawing his daggers as he runs.  Once there he'll make two dagger attacks at advantage, and the first one is his Returning Weapon, which gets +1/+1.

First attack w/Returning Weapon dagger: 20 or 15 to hit and 6 damage

Second attack using two-weapon fighting, with normal dagger: 25 or 8 to hit and 1 damage

Since the second attack was a crit, he'll double the damage for a whopping 2.  :D

Mark will keep moving away to make sure he has good distance from the gnolls and he will shoot his crossbow at the injured gnoll who is engaged in combat. 

attack: 26

damage (with sneak attack): 3 + 9