Nice work, QM.
I'll just add a couple of how-to examples. If you'd really like to see the power of buffing, try the following:
Play Caelum. Choose a Ghost King for your pretender. Give him 3-4 air, 3-4 earth, 1-2 water. Begin the game by researching Alteration 3. Once you reach it, position your GK at the back of the battle board, have him cast Quickness, Mistform, Ironskin, Mirror Image and attack closest. There are very few indy provinces that can stand up to this. If there are a lot of crossbows in the province, add Air Shield before or after Quickness. Caelum is a good nation to try this with since you get 120 design points from taking cold 3, and the ghosts your pretender occasionally spawns are more effective in the cold since they have a chill aura. Also, researching Alteration 3 gets you closer to Alteration 6, and the infamous False Horror spam - a topic for another tutorial
If you'd prefer a less expensive and somewhat quicker-out-of-the-gate pretender, we can take a look at the Astral Wyrm QM mentioned: one of my favorite pretenders. Play most any nation. Slap a few astral on your Wyrm. I like 3. Research to Alteration 1. Position him fairly close to the front of the battle board, have him cast Personal Luck, and attack closest. This works against most anything except heavy cavalry or large numbers of crossbows. The Wyrm is a nice choice for this sort of pretender since he has regeneration, which reduces the chances of afflictions, and has 2 attacks per turn without needing quickness - and therefore without needing water magic. His attacks do a lot of damage since he has great strength, and are also very poisonous. Once you're out conquering, begin Researching enchantment. When you hit 2, you can add Astral Weapon to his script, and when you hit 3, add Astral Shield.