Focus on quality over quantity and pick instants that answer multiple threats
It gives all your creatures vigilance, which it doesn't have itself, and can create tokens
Its got a stellar bonus sheet, five Commander decks worth of new cards and reprints, and a main attraction full of new mechanics and interesting creature-spell combos with the prepare mechanic
Continue the subset of cards that don't care if you connect with an opponent, but rather look to any combat damage dealt, so these become super effective: Five-Alarm Fire, Holy Avenger, Sword of Hours, Lost Jitte, Tamiyo, Field Researcher, and the infamous Umezawa's Jitte
When evaluating artists, we look for strong anatomy, mastery of lighting and rendering, and most importantly, the ability to stay true to the original model of a character
He creates loads of free mana for you, which you can spend on big artifacts that will buff Karn himself