Doer

Doer the Cat is a non-planeswalker black cat that travels from plane to plane with his brother Michi. He has a complete disregard for the laws of planeswalking and physics in general. He wants to hunt the greatest prey he can find so he has a tendency to get into fights he can't win to become stronger.

First years
Doer and his brother Michi were born together, in the same litter. Doer was the first of eight brothers. They were raised in the streets of the plane. They were completely normal cats. Doer was the biggest of all their brothers. Doer was a great hunter and surprisingly stealthy for his size. He hunted for himself and for Michi.

Michi goes missing
One day Michi disapeared and Doer had to track him to a wizard's house. The wizard wanted to kill Michi to perform a ritual to become immortal. Doer jumped and pushed the wizard into the spell, obliterating him. The magic explosion mutated Doer and Michi, giving them consciousness and igniting Michi's planeswalker spark.

Michi sparked to the plane of Ravnica. Doer was left in their home, alone, but he perceived Michi was somewhere out there and he broke reality in the same spot Michi had planeswallked from, appearing at his brother side.

Travelling
Doer and Michi spent some time in Ravnica. Doer tried to date Massacre Girl, fought Ruric Thar for the leadership of the Gruul and killed a Devkarin Lich.

After that, both brothers spent a time in Theros where they met Elspeth Tirel before she got killed by Heliod. Doer fought with Elspeth against the hydra Polukranos, but that got erased from history books. They travelled to the Underworld and Doer fought in one versus one with Erebos. He got defeated and Michi had to escape with him to avoid Doer getting killed.

Both brothers spent a big time in Balix, where Doer spent most of the time mocking the dwarf smith Jhoannes Jhon. He also hunted some of the greatest monsters in the plane, with Doer being recognized as one of the best hunters of the plane. Soon after, they planeswalked away.

The Arena
Doer and Michi arrived to the Arena and the first thing Doer did was pick a fight with the phyrexian Khon Vasq.

Balix, World of Hunt
A few months after leaving the Arena, Doer met Rixos Ker in Balix. With him, he picked a fight with Gryenn Yntedd, an elder dragon of the plane. The fight ended in a draw, because Doer and Rixos escaped Gryenn, but got a spill of the dragon's blood, which Rixos used to get a sword forged.

After the fight Rixos tasked Doer with assembling a team to fight something called Atax in Virteria, Rixos' home plane.

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Doer call his weapon TheMostFabulousWeaponEverMadeInTheHistoryOfAllExistence. The Weapon, as Michi shortens it, is a shapeshifting dagger that can turn into any melee weapon Doer wishes. He commands it with his thoughts. He can call it from the distance to make it reach his paw. The Weapon can also divide itself to allow Doer for more versatility in combat.

Crossing between planes
Even though Doer hasn't got a planeswalker spark he has developed the ability of following his brother in the Blind Eternities. The bad part is that is he spends too much time there he will die as any other individual. The aftermath of the "planescrossing" is some dead fur. Also, Doer can only go to the plane Michi went, he can't travel to wherever he want. If Michi goes from Ravnica to the Arena, Doer can't go from Ravnica to Tarkir, only to the Arena.

After the events of Balix, World of Hunt, Doer has developed the ability to follow other planeswalkers, as he shows to Rixos Ker, following him to the plane of Virteria.

Planes Visited

 * Ravnica
 * Theros
 * Alara (Jund)
 * Balix
 * The Arena
 * Virteria

Trivia

 * Doer did date Massacre Girl once, but the date didn't end well. They only managed to kill forty people in six minutes, under Doer's personal solo-record. They are friends now, and Doer has attended to some of the Rakdos parties.
 * Doer has drunk a beer with Rakdos himself.
 * Doer met Sarkhan once, but the dragonspeaker refused to tell him how to turn into a dragon. The cat has vowed to himself that he will find one day how to do the trick.
 * Doer could defeat Nicol Bolas in one versus one, or at least that's what he says.
 * During War of the Spark, Doer killed three hunderd seventy four eternals. And he got scared by Mowu.
 * The Weapon can also turn into a ranged weapon, but, in Doer's words "that's for weaklings".
 * In Doer's lines of text, the 'meow' goes on every m followed by a vowel, unless it sounds very wrong to me.