They are: Pride (a.k.a Vanity), Envy, Gluttony, Lust, Wrath, Greed (a.k.a Avarice), and Sloth.
Open to interpretation. You don't have to use the word, you can use a synonym (just click on the name of the sin and the link will take you to a list of synonyms for that word).
You can use any brushes, textures, gradients, colors, etc, that you want. You may submit three icons. Icons are due by
Character/Person/Thing's name: Hitsugi
Series/Band name: Nightmare