Bets.

The question is not about "creating a race," but about creating a good, worthwhile race in a short amount of time.

Well, the race was conceived in an hour while I was brainstorming the backstory of the Otherworld.
You can defeat an enemy even without attacking; the main thing is to know them well...
The Irni are the oldest inhabitants of the Otherworld. No one knows where they came from or who they are, but the fact remains: the Irni exist, and they are very dangerous. A harsh fate awaited the Irni in the cruel Otherworld; they were driven from their home into damp and rotten caves. After this terrible event, the Irni swore to take revenge on the ETL, and they kept that oath for a long time...
The Irni, the most powerful of the peoples of the Otherworld (excluding the Blacks), founded the Order of Assassins, renowned for its strength and dedication to the cause.
Basic unit
Lizard
A wild monster found by the League of Avengers, or the Irni, in the underground lakes, turned out to be quite obedient. It fiercely fights for its masters, is immune to fire and water magic attacks, is not very strong, but very fast and determined.
Upgrade
Deepwater Lizard
Found at the very bottom of the deepest lake in the dungeon, thanks to its love of water, it was able to understand the simplest secrets of water magic and, compared to its upper counterpart, possesses the "jet" spell (I'll explain the power of this spell later).

Bugargo
"Bugargo" (meaning "secret" in ancient Elvish) is what the Avengers call the distant relatives of lizards – mini-dragons. These monsters are not subordinate to anyone, but for a good piece of meat, they are ready to tear anyone's throat out. Very strong, but quite cowardly.
Upgrade
Ganirgo (meaning "danger" in ancient Elvish)
"Ganirgo" is interesting because of its proximity to large dragons. This small creature is just as majestic and graceful, and compared to "Bugargo," it doesn't destroy the enemy but poisons it.

Spawn of Skvarn
The Spawn of Skvarn is an Irni who has dedicated his life to learning from the powerful mage-assassin. Frightening in appearance, he brings death from a great distance. The huge length of the damage area is compensated by its weakness.

Upgrade
Fanatic
Fanatic is what the most loyal of Skvarn's spawn are called. Cruel and terrifying killers have lost their long-range damage power over time, but their blades are imbued with the poisonous blood of "Ganirgo" and inflict such damage that the enemy cannot withstand it for 2 minutes and dies a painful death.

Elite unit
Irni Warrior
The Irni Warrior is a serious test for any merchant or rich man who has not brought guards with him. Strong, but accustomed to walking without armor, and unfortunately for him, has a poor physique, and therefore poor defense.

Upgrade
Warden
The Warden is an Irni warrior in retirement, terrifying with his battle scars, frightening every opponent, and compared to his former self, he wears strong armor, but its weight makes his attacks weaker.

Cult Lord
The cult of worship of Skvarn is very influential among the Irni, and its Lord is the closest friend of the ruler. The Cult Lord terrifies everyone, even with his costume, reducing the enemy's initiative. This warrior retained his poisoned blade from his past, but also has a magic staff, thanks to which he has no penalties in melee combat.

Upgrade
Shadow
After death, the cult lord is reborn as a shadow traveling through the world created by Skvarn. But the strongest of them break back into the Otherworld, where they become the strongest of the cult fanatics.

Rotten Dwarf
Rotten Dwarves are traitors to the mountain Brotherhood Empire, terrible spies, hiding in the dark corners of houses, and then reporting to the ruler. These spies are almost invisible and strike from nowhere; the enemy will not know who attacked them.

Upgrade
Brother of Darkness
The time comes, and darkness engulfs the Rotten Dwarf. From now on, he is a Brother of Darkness – eternally calm and motionless. If before he could not run or walk, he could teleport, but now he is carried between battles by servants, and in battle, he emits dark vapors that destroy everything that disagrees with his life theory...

Champion
Assassin
The Assassin, a warrior of the mysterious order, is terrible and mighty... He hides in the darkness, confident that every murder serves a good purpose, but in reality, he is only a weapon in the hands of darkness... But his faith is his strength...

Upgrade
Brother of Mercy
And so, the assassin realizes that he has brought much pain and transforms into a healer with strong armor and confidence in the power of light on earth. His attack is not strong, but his allies, the Brothers of Mercy, can live forever.

And that's the race...