Magna Carta 2

Battle of Highwind Island 10
Complete the battle of Highwind Island.
Story related. You will earn this after defeating the Northern Forces.
Battle of Oldfox Canyon 20
Complete the battle of Oldfox Canyon.
Story related. You will earn this when you defeat Astaroth.
Battle of Cota Mare 30
Complete the battle of Cota Mare.
Story related. You will earn this when you defeat Huaren.
Battle of Dunan Hill 40
Complete the battle of Dunan Hill.
Story related. You will earn this when you defeat Leviathan.
Battle of Ruhalt Basin 50
Complete the battle of Ruhalt Basin.
Story related. You will earn this when you defeat Asmodeus.
First Quest Cleared 5
Clear the first quest.
See "All Quests Cleared" for more info.
10 Quests Cleared 5
Clear 10 quests.
See "All Quests Cleared" for more info.
50 Quests Cleared 10
Clear 50 quests.
See "All Quests Cleared" for more info.
80 Quests Cleared 20
Clear 80 quests.
See "All Quests Cleared" for more info.
All Quests Cleared 30
Clear all quests.
For a list of all the quests in chronological order, see this thread. Be aware that there ARE missable quests, so be sure to follow the guide well!
Co-op Technique: Juto & Zephie 10
Learn Co-op Technique for Juto & Zephie.
You will learn Imperial Blade through story progression just before leaving for Darkblade Fortress. You do not have to use it for the achievement to unlock.

To perform a co-op technique, the two characters involved will need to have the correct weapons equipped (for this specific one Juto needs a 2-handed sword and Zephie needs her fan), then initiate a chain between the characters (see "500 Chain Breaks") and finally press with at least 5 Kan in reserve for both characters.
Style Master: 1 Handed Sword 30
Master Juto's 1 Handed Sword skill tree.
See "Style Master: Shuriken" for more info.
Style Master: 2 Handed Sword 30
Master Juto's 2 Handed Sword skill tree.
See "Style Master: Shuriken" for more info.
Style Master: Hammer 30
Master Argo's Hammer skill tree.
See "Style Master: Shuriken" for more info.
Style Master: Axe 30
Master Argo's Axe skill tree.
See "Style Master: Shuriken" for more info.
Style Master: Rod 30
Master Zephie's Rod skill tree.
See "Style Master: Shuriken" for more info.
Style Master: Fan 30
Master Zephie's Fan skill tree.
See "Style Master: Shuriken" for more info.
Style Master: Fireball 30
Master Crocell's Fireball skill tree.
See "Style Master: Shuriken" for more info.
Style Master: Knuckles 30
Master Crocell's Knuckle skill tree.
See "Style Master: Shuriken" for more info.
Style Master: Aroma 30
Master Celestine's Aroma skill tree.
See "Style Master: Shuriken" for more info.
Style Master: Bow 30
Master Celestine's Bow skill tree.
See "Style Master: Shuriken" for more info.
Style Master: Katana 30
Master Rue's Katana skill tree.
See "Style Master: Shuriken" for more info.
Style Master: Shuriken 30
Master Rue's Shuriken skill tree.
To completely "master" a skill tree, you have to purchase all skills, stat bonuses and upgrades, as well as learn all co-op techniques.

The best way to do this with little issue is to simply not use any of your SP until you have amassed about 700. At this point, save your game. Now spend all your SP and master a tree for each person. Reload your previous save, then master the other tree. Be aware that some of the co-op techniques are only learned through quests, so wait until you have all those before doing this.

To completely master both skill trees for everyone at the same time, you will need roughly 1400 SP per person. This is nearly impossible, since after level 65, the experience you gain vs. the experience required to level up will cause hours of grinding for a single level. Even with the methods listed in the next paragraph, it is extremely difficult to pull off, so do I would highly suggest the first option.

To speed this process up, there is an item called Pendant of Skill that adds +50% SP upon leveling up. You get one from Quest 48 and there is another in a chest just before the Wall of Despair in Belfort. What you'll want to do is be diligent in checking when people will level and equip the item on them shortly before, then switch it over to the next closest person after the previous person levels up, and so on. You can couple this with Belt of Experience to help everyone level more often. There is also a special Kamond called "Seeker" which will add +30% SP upon leveling. You can equip multiple Seeker Kamonds on a weapon and they do stack. You get one free from Quest 33 and more can be purchased in Cota Mare, but only during Celestine's "coming of age" ceremony. They disappear after that.
Weapon Enhanced 5
Use Enhancements on a weapon.
You will first learn the ability to enhance weapons after a meeting in Abazet Port. You should by now have a few Kamonds collected, so open the menu and select the Enhancements option. From here you will have a list of weapons. Some do not have a board to fit Kamonds in to, so choose an appropriate weapon, then select an open slot and finally chose a Kamond to place into the weapon.
Obtained Item Recipe 5
Obtain an item recipe.
See "Obtained All Item Recipes" for more info.
Obtained 6 Item Recipes 10
Obtain 6 item recipes.
See "Obtained All Item Recipes" for more info.

Obtained All Item Recipes 30
Obtain all item recipes.
All you have to do to unlock these achievements is collect the recipe, not actually create the item that it offers. There are a total of 12 recipes to be collected. These are gained mostly through quests and one boss, except three that are found in chests. Those are included in the Quest Guide as well. In the order you will find them:

•Snow Crystal: Defeat the Werewolf Boss in Abazet Field.
•Red Jewel: Complete the "A Tooth for a Tooth" quest.
•Wizard's Rocket: Complete the "Gather Cursed Grass" quest.
•Iron Heart: Complete the "Hunt the Fleeing Soldiers" quest.
•Ring of Conquest: Complete the "Dunan Field's Seeds of Suffering" quest.
•Proof of Soldier: Complete the "Find the Scout, Jeroha" quest.
•Patience & Will: Complete the "Emergency Rescue" quest.
•Golden Frog: Inside a chest to the north of all the tombstones in the Undersea Tunnel while looking for the Cota Mare war documents.
•Reward for Effort: In another chest grouped with Golden Frog.
•Ultimate Shot: Complete the "Ultimate Wonder Potion" quest.
•Mark of the Hero: Complete the "Kill the Inferno" quest.
•Perfect Ring: In the Ruhalt Basin, head north over a brigde near the save pillar that can be found in a clearing east of Belfort and north of the Bluemoon settlement.

100 Chain Breaks 10
Complete 100 chain breaks.
See "500 Chain Breaks" for more info.
300 Chain Breaks 30
Complete 300 chain breaks.
See "500 Chain Breaks" for more info.
500 Chain Breaks 50
Complete 500 chain breaks.
This video from one of the game's producers explains this system very well. For a chain break to occur, you have to successfully perform the following steps in battle:

1.Overdrive: Have a character use more Stamina than the total amount of Stamina they actually have.
2.Chain State: Use the d-pad to switch leader away from the person in Overdrive status.
3.Chain Drive: Again, use more Stamina than you have available with this second person before the original person recovers.
If either leader in the above steps is knocked down, the chain will end and you will have to begin again. Likewise, you can not use items or switch away from Combat mode with either character.

The best combination I found for this is Argo and Juto. Both of them store their Kan internally so it is always available, whereas others need the Kan to be in the air around them which can take some time to build. Don't have either person on focused attack strategy, that way each one can build toward overdrive on different enemies, then unleash their overdrives back to back without getting in each others way or killing the mob too quickly.

The best enemy to grind for these on are either the Phongs or Mighty Lappers outside Abazet. Since they take almost no damage, you can get a whole bunch of Chain Breaks on each enemy before they die. Don't have Zephie in your party when fighting Phongs and don't use Argo's Armor Break against the Lappers though, or they become vulnerable and die quickly.
Viewed Live Drama 1 20
View Live Drama 1
See "Viewed Live Drama 3" for more info.
Viewed Live Drama 2 20
View Live Drama 2
See "Viewed Live Drama 3" for more info.
Viewed Live Drama 3 20
View Live Drama 3
These three achievements are simply a matter of purchasing the DLC mentioned in the Road Map and launching the scenes from the Extras option on the main menu of the game.
Weapon Collector: Juto 30
Collect all of Juto's weapons, including downloadable content.
See "Weapon Collector: Rue" for more info.
Weapon Collector: Zephie 30
Collect all of Zephie's weapons, including downloadable content.
See "Weapon Collector: Rue" for more info.
Weapon Collector: Argo 30
Collect all of Argo's weapons, including downloadable content.
See "Weapon Collector: Rue" for more info.
Weapon Collector: Crocell 30
Collect all of Crocell's weapons, including downloadable content.
See "Weapon Collector: Rue" for more info.
Weapon Collector: Celestine 30
Collect all of Celestine's weapons, including downloadable content.
See "Weapon Collector: Rue" for more info.
Weapon Collector: Rue 30
Collect all of Rue's weapons, including downloadable content.
Again, these all require that you have purchased the DLC pack mentioned in the Road Map. However, these are a bit more difficult in that you have to collect every weapon in the game. There ARE missable weapons, namely because of story progression when shops upgrade their stock, getting rid of weaker weapons. This occurs for both Abazet and Cota Mare. Be sure to purchase every weapon available at a shop ASAP when you come to it, and check upon every new arrival in a city.

If you need to raise money for a group of purchases at a shop, grind away on enemies and complete quests. There is also accessories with "Sacrifice" in the name that will increase SID gain, as well as Kamonds called Golden Clover.

All the weapon locations can be found in chronological order in this thread.

To unlock the achievements, you have to have all the weapons in your inventory, so DO NOT SELL ANY WEAPON, EVER! The only exception to this is the "Wooden Sword" which is Juto's starting weapon. This is removed from your inventory once he grows a pair and starts using real blades. Losing this item does not affect the achievement in any way. From then on though, you need to keep everything.

Secret Achievements

Escape from Belfort 60
Successfully escaped from Belfort.
Story related. You will earn this after defeating Beelzebub Complete.
Assault on Ruhalt Plateau 70
Completed the assault on Ruhalt Plateau.
Story related. You will earn this after defeating Alex.
Game Completed 80
Completed the game's main story.
Story related. You will earn this after watching the end credits.
Co-op Technique: Argo&Celestine 10
Learned Co-op Technique for Argo & Celestine.
You will learn Heavenly Storm automatically after defeating Jopa. You do not need to use it to unlock the achievement.
Co-op Technique: Zephie & Rue 10
Learned Co-op Technique for Zephie & Rue.
You will learn Blizzard Edge automatically once you arrive in Belfort. You do not need to use it to unlock the achievement.
Co-op Technique: Juto & Crocell 20
Learned Co-op Technique for Juto & Crocell.
You will learn Nova Slash during the "Rescue Marith" quest. You do not need to use it to unlock the achievement. You do need to use it to complete the quest though.
Co-op Technique: Celestine & Rue 20
Learned Co-op Technique for Celestine & Rue.
You will learn Iced Lightning Burst during the "A Stony Smile" quest. You do not need to use it to unlock the achievement, nor do you need to use it to complete the quest