Civ Bonuses:
Villagers +5 carry capacity.
Monks gain +5 hit points every time a monastery tech is researched
Infantry trained 15% faster
Team Bonus
Gold generated by relics is increased by 33%
Unique Unit:
Jaguar Man: It is an infantry unit with a bonus vrs other infantry. It costs 60 food and 30 gold.
Unique Tech:
Garland Wars: It gives all infantry units +4 attack vrs other infantry.
Tech Tree:
Have all monastery techs.
Have all infantry and archer upgrades.
Have Halbardiers.
No mounted units of any kind.
No stables or cavalry upgrades.
No gunpowder units.
Comments by AOK:TC deigners paraphrased by Cherub BroacLanders:
Aztecs are an infantry based civ. They have some of the most effective infantry units in the game. Because infantry are vulnerable to archer fire, the Aztecs rely heavily on both their fully upgradable skirmishers and eagle warriors. Although Aztec Eagle Warriors lack the massive hit points of the Mayan ones, they are still critical units in the Aztec army. Their fast speed, anti-archer and anti-siege capabilities are invaluable to the Aztecs.

The Aztecs have an above average economy. Although their bonus is not as good as some of the other civs, it will still keep them competitive.

Another main strength of the Aztecs is their monks. They have the best monks in the game. Not only do they have all the monastery techs, but their monks have massive hit points as well. Fully upgraded, their monks can reach 85 hit points! Since the Aztecs will usually have several monks on hand, their team bonus is of particular use to them. Relics should be much more worth the time it takes to track them down.

The Aztecs are particularly vulnerable to handcannoners. Since they lack heavy cavalry, their only real hope of countering them is with onagers, and Eagle Warriors. Since the handcannoners now do even more damage, units like skirmishers with high pierce armor are only marginally more effective against them.

The main advantages of the Aztecs is their powerful infantry, ability to counter the infantry of others and their very strong monks.

The main disadvantages of the Aztecs is their lack of fast mounted units, their vulnerability to gunpowder units, and their lack of any gunpowder units of their own.