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So, here is the theoretical solution to the problem:
Option 1: Titan's Roar
1. We have a level 20 Tazar (10-10-0-0).
Artifacts: Titan's Roar, Elixir of Life, Cloak of Speed, Amulet of Speed.
2. Unit parameters: Wyvern Monarch defense 14; Dragon Fly attack 8, damage (2-5).
As a result: Tazar, with an expert Armor skill, has a damage reduction of 15% + 15% * 0.95 = 29.25%. This means that the Snake will hit any of Tazar's units, dealing only 70.75% damage.
The Wyvern's defense is 6 higher than the Snake's attack, plus 10 defense from Tazar. In total, 16, which means a further damage reduction of 32%. As can be seen from the calculation, the Snakes will attack the Wyvern, dealing only 38.75% damage.
That is, 18 flies can deal 18 * 0.3875 * (2-5) = (13.95-34.9) damage.
And now, the battle itself:
The Wyverns, accelerated by artifacts, start the battle.
We hit one of the left Snakes with magic, and it flies away to D1. Only two flies will reach the Wyverns, dealing (27.9-69.75) damage, and our little Dragon has 91 HP.
Next, the Elixir restores all health losses.
We kill the second fly (we choose from the whole ones), and three remain, one of which is corrupted. Even if all three snakes remained intact, they would deal (41.85-104.625) damage. It is clear that a lot of bad luck is needed for them to defeat the Wyvern. And after that, they have no options!
Option 2: Cursed Armor.
The only difference is in how the battle is conducted. The cursed flies will hit at most, dealing 5 damage, and there are only 5 of them. :D. As a result, the wyvern will eventually defeat them all.
Option 1: Titan's Roar
1. We have a level 20 Tazar (10-10-0-0).
Artifacts: Titan's Roar, Elixir of Life, Cloak of Speed, Amulet of Speed.
2. Unit parameters: Wyvern Monarch defense 14; Dragon Fly attack 8, damage (2-5).
As a result: Tazar, with an expert Armor skill, has a damage reduction of 15% + 15% * 0.95 = 29.25%. This means that the Snake will hit any of Tazar's units, dealing only 70.75% damage.
The Wyvern's defense is 6 higher than the Snake's attack, plus 10 defense from Tazar. In total, 16, which means a further damage reduction of 32%. As can be seen from the calculation, the Snakes will attack the Wyvern, dealing only 38.75% damage.
That is, 18 flies can deal 18 * 0.3875 * (2-5) = (13.95-34.9) damage.
And now, the battle itself:
The Wyverns, accelerated by artifacts, start the battle.
We hit one of the left Snakes with magic, and it flies away to D1. Only two flies will reach the Wyverns, dealing (27.9-69.75) damage, and our little Dragon has 91 HP.
Next, the Elixir restores all health losses.
We kill the second fly (we choose from the whole ones), and three remain, one of which is corrupted. Even if all three snakes remained intact, they would deal (41.85-104.625) damage. It is clear that a lot of bad luck is needed for them to defeat the Wyvern. And after that, they have no options!
Option 2: Cursed Armor.
The only difference is in how the battle is conducted. The cursed flies will hit at most, dealing 5 damage, and there are only 5 of them. :D. As a result, the wyvern will eventually defeat them all.