The following algorithm is how to calculate damage:

Damage = ((((2 * Level / 5 + 2) * AttackStat * AttackPower / DefenseStat) / 50) + 2) * STAB * Weakness/Resistance * RandomNumber / 100

So, I will just make up certain things:

Level: 100

Sp. Attack Stat: 170 (slightly larger base stat)

Base Power: 150

Sp. Defense Stat (Scyther): 60 (slightly lower base stat)

STAB: 1.5

Weakness/Resistance: 1.5

RandomNumber: 100

So, the formula BECOMES...

Damage = ((((2 * 100 / 5 + 2) * 170 * 150 / 60) / 50) + 2) * 1.5 * 1.5 * 100 / 100

Damage = (((42 * 170 * 150 / 60) / 50) + 2) * 1.5 * 1.5 * 100/100*

Damage = ((17,850 / 50) + 2) 1.5 * 1.5 * 100 / 100

Damage = (357 + 2) * 1.5 * 1. 5 * 100/100*

Damage = 359 1.5 * 1.5 * 100/100

Damage = 538.5 * 1.5 * 100/100

Damage = 807.75 * 100/100

Damage = 8,0775 / 100

Damage = 807.75

Damage = ~808

Metal Sound halves Scyther's defense, therefore doubling the power to **1616**. Forest Curse also gives it another 1.5 weakness thing, making it **2424**.

Until you actually give exact things, then that's roughly the answer. :3

**TL;DR: The answer is roughly 2424 damge.**

Hope I helped. :)

Source: Serebii