Skill build1 – Press the Attack
2 – Moment of Courage (Overwhelming Odds)
3 – Moment of Courage
4 – Press the Attack (Overwhelming Odds)
5 – Moment of Courage
6 – Duel
7 – Moment of Courage
8 – Press the Attack (Moment of Courage)
9 – Overwhelming Odds
10 – Press the Attack
11 – Duel
12 – 15 - Stats (Press the Attack and stats)
16 – Duel
17 – 25 - Stats
Starting items
2x Ancient Tango of Essifation – this will allow you to be more aggressive early game. They also come in handy against those pesky ranged heroes.
2x Clarity Potion – since commander has a relatively small mana pool, you'll need mana to keep spamming overwhelming odds or being extra agressive using press the attack.
2x Gauntlets of Ogre Strength – aside from giving you extra hitpoints, you will want to make an urn later on for mana and heal.
Core items
Phase Boots - most of the time the extra movement boost and phasing ability will be enough to catch anyone with your duel. The bonus damage doesn't hurt either.
Blade Mail - an absolute must have for a duelist, it gives you mana to keep yourself and allies alive with press the attack, you get bonus damage and armor. Also never forget to activate it before the duel, especially against carry heroes.
Urn of Shadows - as i mentioned before, it's useful to keep yourself in the battle or as an extra damage boost during the duel.
Luxury items
Battle Fury, Desolator, Buriza-Do Kyanon, Assault Cuirass
In late games, after you've won plenty duels, you'll want to be able to do something with that damage. Battle fury will make you an amazing pusher, as well as give you the power to take on multiple heroes. Desolator will give you heavy extra damage to break even the toughest of tankers. Buriza also does this, but the critical hit damage doesn't work in a duel. Assault curiass is the most advised one, because you'll have a lot of damage already thanks to duels, while the armor will give you extra tankiness.