This is just a guide in progress because I recently started playing ranked and realized my AD Pantheon build wasn't suitable for 3v3 matches. So I'm working out this idea and I'd really like your guys' -Constructive-, operative word, criticism. Thanks in advance I'll post more as time goes on.

I choose his stun first because Aegis of Zeonia seems to help us gank early on. After that I want to max Spear Shot asap because it scales damage the fastest for the lowest mana return. Heartseeker Strike is a fine followup to Aegis but it doesn't scale quickly enough to require more than one rank initially. Remember guys, this is just how I see Pantheon, I welcome any insight.

With this build I'm not sure the best method to farm. It's an easy jungle build. Generally I farm on my AD build with Ionic Spark and Wriggle's Lantern or Executioner's Calling.

I feel like this champ setup would do well solo'ing top lane in 3v3 because with his stun and range on spear shot not a lot can get away. Also, stacking exhaust will keep them from getting too far. If paired with an AD or AP champ at bottom I think as an initiator Panth is great. Let him launch his stun and the laning partner unleash everything they've got upon the enemies.