Nishant's Pet

This thing is the master of dark possession, and has crept its way above its own general to an S rank. Only obtainable through war shop and special events.

Overview
Nishant's pet is a Dark monster known for his multi possession, double damage possession, and making monsters weak to darkness attacks. The reason he is such a good monster is mostly his damage, it's just... great.

Positives
 * Great Damage
 * Possession
 * Makes weak to Darkness

Negatives
 * Slow
 * Cooldowns

Movesets
Deathly Killer
 * Gloomy Doom
 * Soul Piercer
 * Shallow Yell
 * Nocturnal Tackle
 * 3 Speed Runes

Here is the common skill set. It is, with little debate, the best and most useful set of moves.

Counters
Lux Aura and Metalhëad can pretty much get rid of Nishant's Pet without much complaint. You might want to also try Rador