Shadow Planeswalker

I am Shadow, a planeswalker, darkness itself, and I wield darkness: I can summon shadow warriors and the shadows of defeated enemies, summon dark weapons with a variety of effects, from Devourer to Dark Fire, but my main abilities are the Dark Sword, Shadow Leap, Shadow Merge, a hard-to-pierce dark shield, and my ultimate, "Bury 10 Shadows." I resemble a masked, hooded dark assassin, but my appearance is armor crafted from a variety of metals and alloys from different worlds, marked with countless seals that make this armor impenetrable to anyone or anything. I don't wreak havoc; I wander through worlds and simply explore them. A special watch helps me with this: it depletes with each jump but recharges over time from the world's mana. I have an AI assistant, Janet, who helps me through these hours. I'm 16 years old. To kill me, you have to kill the darkness itself, every dark corner, every shadow and darkness in the world. Caffeine allergy , who are you, and where have I ended up?