Adray, having stood aside, smiles at Ordrag's quick thinking.  An arm wrestling match, that was smart and played right up into the creatures seemingly violent nature.  His draw dropped as he pulled out the silver long sword.  That, was quite the bet.  With something like that he hoped Ordrag bet for more than just the tooth.  

"My friend is quite confident in his strength, otherwise he'd not wage such a fine blade.  Are you sure you want to bet that.  I mean, its been bathed in so much blood and still has so much use for us.  Oh wait, I think thats a speck of dried blood there, let me just wipe that clean," Adray says and hesitates before moving in.

The laugh became louder: "Keep your toothpicks to yourself! This is not a weapon - that one is!" What most of the gnomes were keeping on them looked like quite big and dangerously looking Sickle - as different from ordinary light toys that druids like so much, as a draft horse differs from a pony. To prove the point, some of the mad gnomes were carrying disproportionately big axes and mauls with them, and were doing it with ease too.

Ordrag shrugs and returns the sword to his kit. Then he pulls out a small vial and jiggles it around. Me have a healing potion here. But me won't give it up cheaply. What are you gonna bet?

Fran's eyes would follow the point. She'd look the sickly looking sickle up and down before she'd shift her weight onto the other foot. If Ordrag's offer was still not enough, she'd pat a finger on her chin before gesturing to the Sickle herself. "Can make it stronger fer ya with an enhancement." The artificer would offer.

The redhead would pull out Lucy and her crossbow, gesture to her armour, then Ordrag's radiant enchant (it was on his right? or choirs? I lost track who had it.) and then Polly's focus should she present it. "These are examples. We can demonstrate if ye want."

(Edited to add demonstration as per suggestion)

"Make my sickle magic..." Redcap nodded with each word and looked like he really liked the idea. The more strange was the final answer in a quite angry yell: "Keep away from my Sickle! No trust to strangers!"

Mad gnome turned to both warriors (they did laugh but the bloodied weapon surely caught attention as well as attitude): "How about a fight? I win - I cut your finger, you win - I give you the whole hand!" Indeed, the little monster produced a severed hand (human, by the look of it). He was so eager, that he dance on place.

Ordrag thinks for a moment, weighing up the options, then replies: Me don't want boring hand? Me want something different, something special. If me win, you give me the tooth from the flameskull. If you win, me give you the finger.

Choir hopes that her healing powers can bring back that finger, if Ordrag loses.  But she has confidence in his strength.

Polly wonders if it would be cheating to cast enlarge on Ordrag in the battle, it would certainly give him an edge. She leans in an whisper to Adrey what he think.

(Polly can try but reaction can be ... harsh)

"What tooth?" The grimace on his face probably was supposed to symbolize innocence. "Do not know any teeth! Can take yours, though!" Happily declared Grubba with a mad grin and then, without a pause agreed: "All right, you get the tooth, but I get all yours!" 

"We begin!" The other Redcaps formed a circle around Ordrag and Grubba (whether he wanted or not, he was in now) pushing out everyone else. "Take this, toothless!"

He jumped at Ordrag raising his sickle and loudly stomping the ground.

Initiative: 3

Initiative: 3+2

Ordrag sees the little twerp tense before the spring, and lunges in first with a flurry of weapon strikes...

Action: Attack/Longsword.
Attack#1: 12 Damage: 12 slashing.
Attack#2: 22 Damage: 13 slashing.

Bonus Action: TWF/Warhammer.
Attack: 15 Damage: 11 bludgeoning.

Action Surge: Attack/Longsword. 
Attack: 20 Damage: 11 slashing.

 Choir emits the sound of an excited audience cheering at Ordrag's magnificent display of battle expertise!

Every single attack hit, extracting angry noise from the gnome, every single draw blood (other Redcaps cheered and yelled with every blow), but it did not kill little creature on spot. It looked like the idea of surrendering was an alien concept to Redcaps, Grubba attacked - he jumped up and kicked Ordrag with both its iron boots:

DC 14 Dexterity saving throw or take 12 bludgeoning damage and be knocked prone.

DEX save: 16

Ordrag is floored (both literally and figuratively) that such a little creature can kick so hard. If it had kicked him in the face he probably would have lost all his teeth after all. But he picks himself up off the ground, grabs his weapons and attempts to smash the angry garden gnome again.

Action: Attack/Longsword.
Attack#1: 21 Damage: 13 slashing.
Attack#2: 19 Damage: 13 slashing.

Bonus Action: TWF/Warhammer.
Attack: 15 Damage: 7 bludgeoning.

The warhammer strike was unnecessary - after first slash of the sword the Redcap exploded into a cloud like the one puffball mushrooms leave if you step on them, all what was left is the weapon and the pouch, that both dropped to the ground. A lone tooth rolled out of the pouch but the cheering crown (now in mad excitement roaring and punching each other) ignored it completely. One of the most grumpy looking Madcap sput in it's direction mumbling something like "lucky tooth my ass!" and immediately punched his neighbor.

Ordrag picks up the tooth, happy to have one extra rather than several fewer. He also takes the sickle as a souvenir. Shame the boots didn't remain behind.

Barnabus was watching the fight from some distance, pretending it has nothing to do with him - but now he approached. "Did you get it?" whistled he with eye sockets shining with anticipation.

Ordrag holds out the tooth. Yeah, bro. Here it is. But a favor for a favor, eh? Now you help us get what us need.

Brief shot of magic - and the tooth took it's rightful place in skull's jaws. Barnabas happily clicked his restored teeth together: "Good, good. I am all happy to return the favor and praise your group to Maggy. Keep it up and she might threw more good stuff in your deal. Or is it something else you wanted from me?"

Ordrag can't think of anything else they need, but he looks to his companions in case they have any requests.

"You don't happen to have som magic books or scrolls with magic suitable to fight the demons and devils do you?" Polly asks hopefully.