I saw in the Off-topic chat by @ArinSka
a discussion discussing how to kill a planeswalker in real life, so I'm doing it in MTG.
This is the world of Grodinia, a land of immense mana and enough planeswalker sparks to bless all of Innistrad. Both sparks and planeswalkers themselves are plentiful here and are much more powerful than most other creatures here. Since they occasionally get bored but don't want to leave their plane, the let challenges take them on for their spark. You are one of those challengers.
Create a Creature (Legendary or Non-Legendary) with CMC 0-3 as your competitor in a planeswalkers challenge (I will create the planeswalker challenging you)
Create up to two signature card with CMC 0-3
Create a brief story about your character and I will start your adventure.