Edward can don a variety of armor found throughout Assassin's Creed 4: Black Flag, but one of the best is the Templar armor, which drastically increases his defense, allowing him to take far less damage compared to his normal gear. Once you've obtained the first key from the story mode, you can hunt down the remaining three keys via the following quest line.
Templar Hunt 01: Opia Apito
Mission 1: The Taino Assassin
Head to the Castillo de Jagua area to find a Templar hunt at Cayman Sound (332,332). There are three ships in the area that will attack. With even a moderately upgraded Jackdaw, you should be able to take them down with ease. Swim to shore and head for the Templar hunt marker. The assassin, Opia Apito, challenges you to a hunting competition. You must kill and skin more hutia than her. Kill four hutia and a white jaguar attacks. Climb the closest tree or rock formation and hit the jaguar with a sleeping dart for an easy kill. Skin the jaguar to initiate a cut scene and complete the first mission.
Mission 2: Templar Ships
Head back to the Jackdaw, sail around to Grand Cayman (397,324) and dock at the harbor. Speak to Opia Apito who is standing on the docks. Follow her, then locate Alvin and eavesdrop on his conversation. When you reach the designated area, Alvin is standing in the larger group of people. Use Eagle Vision to easily spot him, then head to the top of the nearby hut to safely eavesdrop on his conversation.
When the conversation comes to a close, kill Alvin and steal the ledger. Alternatively, you can sneak up behind him and steal it, but where's the fun in that? Once you have the ledger, the mission is complete.
Mission 3: Right-hand Man
Follow the marker to find Opia Apito and speak to her once more. Follow her again, then hide in the nearby stack of brush when instructed. When the target runs, chase him down. You don't have much time so stay as close to Vargas as possible. When he reaches the harbor, it initiates a cut scene in which he jumps to a ship. Your next objective is to reach the wheel of the Jackdaw and give chase.
Incapacitate and board Vargas' ship. It won't put up much of a fight, but watch out for fire barrels as you give chase. Board Vargas' ship and kill him for another cut scene to complete the mission.
Mission 4: The trail of Lucia Márquez
Sail to Pinos Isle (332,469) to find two ships patrolling the harbor. You can take out one ship and swim to shore fairly easily, or you can take out both ships if you're feeling especially grim. Head ashore and speak to Opia again to begin the next mission.
Tail the guard. If you stay alongside Opia, you won't have much to worry about. Kill the guards ahead using the explosive barrel to the left, stealth attacks or a full frontal attack. Once the guards are down, Opia calls over a few more to entertain you. Make sure she's not under attack and take out the remaining guards, then chase down and kill Lucia Márquez. Every time she stops, she takes a shot at Opia, so kill her quickly. Once she's dead, the mission and side quest are complete.
Templar Hunt 02: Rhona Dinsmore
Mission 1: Bureau Under Attack
Head to Havana to find the next Templar hunt mission. Head to the start point (240,607) and speak to Rhona Dinsmore to start the mission. Help her defend her position by attacking the guards and moving powder barrels to the designated entrance. You must carry barrels to each of the three entrances to the defended area, one entrance at a time between attacks. Defeat all four waves of guards to complete the mission.
Mission 2: A Thief in the Market
Speak to Rhona once again to begin the next mission. Your first objective is to locate a pickpocket. Once you find him, he happens to have just pickpocketed a soldier... poorly. As he runs from the solider, chase after him. When he stops, kill him and then loot his pockets to complete the mission.
Mission 3: Arms Race
Head back to Rhona one more time and speak with her to begin the mission. Your next objective is to find and ignite three guarded powder reserves. You can sneak into each structure, stealthily taking out the guards, then ignite the powder or you can storm in and do it the gladiator way. The choice is yours, so long as you get the job done. Once all three are destroyed, the mission is complete.
Mission 4: Flint's End
Go back and talk to Rhona to begin the next mission. Follow Rhona until she reaches the heavily guarded area where Flint is found. Ignore all of the guards and head to the back of the area to find Flint. Take him down quickly, as there's no need to engage any of the other guards. Once Flint is down, escape the zone and become anonymous to complete the mission. Take to the rooftops to make it easier to lose the guards.
Templar Hunt 03: Anto
Mission 1: The Maroon Assassin
Head to Kingston to find Anto and the next Templar hunt side quest. Speak with Anto to begin the mission, then head over to the location of the guards and eavesdrop on their conversation. Start on the bench, then follow the men as they move. When they stop, blend in with the crowd to avoid detection.
When the conversation ends, head to the next set of guards and eavesdrop on their conversation as well. Take to the rooftops here to avoid detection. When the guards are warned that someone is listening in, they make a run for it. Follow one of the guards and tackle him to the ground to complete the mission.
Mission 2: Recruiting Maroons
Speak with Anto again to begin the next mission. Escort him as you head to each area and liberate the slaves. The slaves aren't very heavily guarded, but if you want to have a little fun, hire the drunks near the first slave and they'll help you fight the guards near all three slaves. Free all three slaves to complete the mission.
Mission 3: Under Attack
Head back to Anto to begin the next mission. Your objective here is to defend Anto bureau. There are three waves of attackers. You can lessen their numbers by weeding them out between attacks, but this is not necessary. You can complete the mission just as easily by simply waiting at the bureau for each wave. Defeat all of the attackers to complete the mission.
Mission 4: The Commander's Ruse
Meet up with Anto one last time to begin the mission. Follow Anto and tail the guards until they enter the compound. Sneak through the compound using Eagle Vision to locate Kenneth Abraham. He can be found near the northeast corner of the compound. Once you have located him, you must kill him. If you approach from the rooftops, you can use an aerial assassination. You can also wait in the tall brush, or go for a full frontal assault. As long as Kenneth dies, that's all that matters. Once he's dead, escape the area to complete the mission and the side quest.
Templar Hunt 04: Vance Travers
Mission 1: Oh Brother...
Sail to Nassau to find Vance Travers. Speak with him to begin the mission. Your first objective is to locate Upton's men. Head to the designated area and use Eagle Vision to spot them. Once you've found the men, head to the rooftop to follow them and eavesdrop on the conversation. When they reach the compound you must find Upton. He's right in the center of the compound. Use the trees to maneuver above him, then assassinate him from above. Oddly enough, you won't actually assassinate him, but the mission will be complete either way.
Mission 2: The Other Brother
Head back to the bureau to speak with Upton to begin the mission. Follow him until you are instructed to hide in the foliage. Follow Upton and Vance, using the rooftops to the left of the two men to remain undetected. When they stop in the middle of the square, a thief appears just ahead. Stay on the rooftop and wait for the thief to approach, then kill him with an aerial assassination.
Continue tailing Vance and Upton, staying to the left of the two men. A second thief attempts to attack the two. Stop him before he gets within visual range of the men. In this case, you can simply walk right up to him and assassinate the thief. Just make sure you're out of sight of the two men when you do this.
A third thief makes a attempt on the two brothers the next time they stop. Once again, if you stay to the left of the two men, you should have no trouble taking him down while remaining out of sight. Simply walk up to the thief while he's hiding and finish him off.
When the two split up, continue following Vance until he meets up with his female friend. You need to eavesdrop on the conversation, but there aren't many places to hide. Use the trees and rooftops to maneuver around to the other side of the couple, then hide in the brush near the well before they come to a stop.
After a brief conversation, you must locate Upton's killer in one minute or less. Quickly head to the designated search area. Activate Eagle Vision and look down from the rooftop. The suspicious individual moving around like an assassin is your target. You should have no trouble taking him out from the rooftops to complete the mission.
Mission 3: Upton's Sorrow
Head to the tavern and speak with Upton to begin the next mission. After the cut scene, you must defend Upton and beat up a gang of men with only your bare hands. Stay close to Upton as you attack the mob to ensure his safety. With all of the men defeated, escort Upton to safety. Pay off the dancers to leave, then defend Upton against the two sets of guards that attack after he relieves himself. With Upton safe, your mission is complete.
Mission 4: Queen of Pirates, King of Fools
Meet up with Upton once again and speak with him to begin the mission. Your next objective is to locate Vance. Head to the search area and be careful of the two crocodiles lurking in the water. Take them out with a sleep dart if you don't want to worry about them.
Make your way through the area, taking down the guards in a stealthy manner, or with brute force if you prefer. Vance is located in the middle of the search area, on the far east side. Once you find him, the objective is to kill him. Use the trees to get above Vance and assassinate him from above, then chase after Jing Lang as she flees the area. Kill her as well to complete the mission and the entirety of the Templar hunt side quest.
How do I get the Templar armor?
Head to your hideout, Great Inagua, and find the Templar armor within the manor (845,468). With the four keys from each of the previous side quests, and the original key from the story mode, you can now open the cage with the Templar armor. Equip the armor to gain a defense boost.