Most of this content was researched and posted before by Good_Guy_Greg. Most of the credit go to him. He gave up on his guide, and no longer updates it. For the sake of the Esgrima 2 community, I decided to re-write the guide with some more detail. Feel free to write in the comments what I missed. During the time of me starting to write this I am just a Level 23 Musketeer. That’s why I appreciate you posting any of the things you can update, so I can add it to the guide.
If you’re looking for a specific drop, all credit goes to Icomanser: https://docs.google.com/spreadsheet/ccc?key=0ArxJ_Sn6K4I4dFBjeEpFS3I3cTNFQ0tPYmVQTzZUM3c
Railroad Junction (Level 5-8)

Boss name: Banditor
Strategy: A few musketeers with the Critical Shot skill can handle this guy easily.
Abilities: 1.Continuously stabs a target 4-5 times. (Very dangerous for squishy targets, even for warriors, guardians would say “bitch please” to this.)
2. He also does a frontflip slash, I would assume it deals moderately high damage, something like the Guardian’s Lance Strike.
Health: 850
Elements:
Weaknesses: No info
Strengths: No info
Drops:
Gems:
Equipment: Level 12 rare hats and helmets, level 1 rare rings, level 8 rare rings
Recipes: None
Other: Coat piece
Selva Temple (Level 10-12)

Boss name: Pontero
Strategy: Unless you have a player or two, who have been farming Pontero for a while, and have very good gear, you should get a cleric for this fight. A warrior or guardian is also reccomended. Pontero is also easily handled with the Critical Shot skill.
Abilities: 1. Area of Effect attack.
2. Attack Increase buff.
Health: 2,500
Elements:
Weaknesses: No info
Strengths: No info
Drops:
Gems: None
Equipment: Level 10 rare weapons, Level 10 rare armors. (This gear is quite reccomended, it carried me all the way up to 25-ish.)
Recipes:
Other:
Montero Hideout (Level 13-15)

Boss name:Grand Montero
First boss to have some kind of ending cutscene, monologue, etc. You can also find Montero in the prison after you defeat him. :P
Strategy: Definetely bring a cleric, and people who are strong enough to hold the front line. Fire mages would seem to be particularly helpful in this fight. Musketeers can still help out with Critical Shot and Ultimate Shot for damage output, but it’s not as helpful it was on the last few bosses.
Abilities: 1. Just like Banditor, Grand Montero has an ability where he continuously stabs a target. 4-5 times.
2. Montero also has an AoE.
3. He has a Defense buff.
Health: 12,500
Elements:
Weaknesses: No info
Strengths: Plant
Drops:
Gems: Darkness gems
Equipment: Level 1 rare shoes, Level 10 rare shoes, level 15 rare rings, Strength Necklace
Recipes: Level 15 shoes recipe, Level 10 Ring Recipe (Warrior Ring, the one that brings you through hell while crafting)
Other: Warrior Stone, Quality Thread
The Cabin (Level 14-17)

Boss name: Pirate Captain
This is probably going to be the first lengthy boss fight you find. A guardian is reccomended, but not neccesary. Cleric is obligatory.
Abilities: 1. An AoE attack, where he shoots from his cannon, and the projectiles fall back on everyone except him.
2. A defense lowering grenade, also AoE.
Health: 44,500
Elements:
Weaknesses: Mechanic
Strengths: Water, flying
Drops:
Gems: Lightning gems, +10 attack gem (ring)
Equipment:Level 10 rare boots, Level 22 rare hats and helmets, level 22 rare rings, Endurance Necklace, Wisdom Necklace, Level 10 rapier
Recipes: Level 20 armor recipes, Level 20 rapier recipe
Other: Pirate Hat Badge
Dark Ocean (Level 20-23)

Boss name: Dark Deep Sea Predator
Due to the logic, that you would only get access to making a guardian AFTER killing this little fella’, you would think that it is doable without a guardian. Well, you would be right. But, this boss battle is a LOT easier if you have a guardian, or better, two guardians on the front line. Cleric is a must as well. I would actually reccomend getting your lightning weapons from a quest in Port Ville, before facing this guy.
Abilities: 1. Sonic Wave, is a double hit AoE. It also causes a common bug that makes you appear alive, even though in reality you’re flopping on the ground, bleeding, with your life flashing before your eyes.
2. A stun, also causes previously mentioned bug.
Health: 82,400
Elements:
Weaknesses: Ice, lightning, plant
Strengths: Fire
Drops:
Gems: Water, plant gems, +50Hp (ring, necklace)
Equipment: Lucky Necklace, Level 15 Back Decoration
Recipes: Level 20 weapons (not entirely sure which ones)
Other: Predator fin, crafting hammer, sewing needle, Guardian Talisman (for Guardian quest chain)
Divertida Palace (Level 22-25)

Boss name: Maestro
Health: 65,000
Elements:
Weaknesses: Ice, lightning
Strengths: Water
Drops:
Gems: Flying gems
Equipment: Level 23 Rare Weapons, Level 23 Rare Armors
Recipes: Level 20 rod
Other: Divertida Hat Badge
Sky Tower (Level 30-33)

Boss name: Warlord Zirhon
Health: 79,000
Elements:
Weaknesses: Water
Strengths: Fire
Drops:
Gems:
Equipment: Level 23 Rapier
Recipes: Level 30 Weapons, Level 20 Helmet, Level 19 Heavy Boots
Other: Zirhon Blades, Warrior Stone
Vuelo Airship Deck (Level 32-34)

Boss name: Battle Counquerer
Health: 150,000
Elements:
Weaknesses: Flying, water, beast
Strengths: Light
Drops:
Gems: Mechanic gems, +50Atk, +8Def
Equipment: Level 29 Ring
Recipes: Level 30 Armors, Level 30 Hat
Other:
Earthstone (Level 34-37)

Boss name: Toxico Spider
Health: 215,005
Elements:
Weaknesses: Fire, light
Strengths: Plant, beast
Drops:
Gems: Beast gems, 1%critchance(weapon)
Equipment: Level 36 rare weapons
Recipes: Level 30 Helmet, Level 20 Necklace
Other: Toxico Hat Badge
Polar Thundra (Level 42-43)

Boss name: Viscount Vilhelm
Health: 100,000
Elements:
Weaknesses: Fire
Strengths: Water
Drops:
Gems: Ice gems, +10Mana
Equipment: Level 40 rare armors and clothes, level 42 rare hats and helmets, Level 36 ring
Recipes: Level 30 Female Hat, Level 40 Book,
Other: Frozen Ice Spear, Dragon Skin
Suelo Congelado (Level 43-45)

Boss name: Ice Hearted Prince
Health: 266,000
Elements:
Weaknesses: Fire
Strengths: Water
Drops:
Gems: Ice gems, +100Hp (Armor/Head),
Equipment:
Recipes: Level 40 Light Armor, Level 40 Sabre, Level 40 Rod, Level 40 Dress, Level 40 Pistol, Level 40 Shield, Level 40 Hat, Level 40 Lance, Level 40 Coat,
Other: Ice Crystal
Sombra Dungeon (Level 44-47)

Boss name: Destroyer
Health: 117,080
Elements:
Weaknesses: No info
Strengths: No info
Drops:
Gems: +20 defense gems (for helmet and armor)
Equipment: Level 43 Ring, Level 37 Boots, Level 30 War Trophy Back Decoration
Recipe: Level 40 Suit, Level 40 Helmet, Level 40 Ring, Dragon Horn
Other: Dragon Skin
Ruined Eden (Level 44-46)

Boss name: Angel of Destruction
Health:
Elements:
Weaknesses: Light
Strengths: Plant, darkness
Drops:
Gems: Light, darkness gems, +8Defense (can be enchanted to ring), +30Mana (Armor and Head).
Equipment: Wooden Cross Back Decoration,
Recipes: Level 40 Rare Rapier, Dragon Horn, Level 40 Ring
Other: Angel Feathers
Arfildex Gardens (Level 46-48)

Boss name: Prince Dulahan
Health:
Elements:
Weaknesses: Water
Strengths: No info
Drops:
Gems: Earth, +1 Dodge (Armor and head)
Equipment: Level 50 Ring, Level 49 Lance
Recipes: Level 50 Female Hat, Dragon Horn, Level 40 Necklace
Other: Dulahan Arms
Fuego Mountain (Level 47-49)

Boss name: Grand Lava Keeper
Health:
Elements:
Weaknesses: Water, Earth
Strengths: Beast, Ice
Drops:
Gems: Fire gems, +50Hp (ring)
Equipment: Level 49 Rare Weapons (Except for Shield)
Recipes: Level 50 Hat, Level 50 Rapier, Level 50 Shield, Suerte Necklace, Secret War Factory Key
Others: Evil Stone, Black Gold, Dragon Skin, Lava Hat Badge
Escondido Chateau (Level 48-50)

Boss name: Fuerte Ira
Health: 350,220
Elements:
Weaknesses: Light
Strengths: No info
Drops:
Gems:
Equipment: T1 Weapons, T1 Armor
Recipes: Level 50 Dress, Level 50 Greatsword
Other:
Escondido Chateau (Level 48-50) Continuation of Fuerte Ira

Boss name: Void
Health: 450,000
Elements:
Weaknesses: Light
Strengths: No info
Drops:
Gems: +10Attack gem
Equipment: T2 Weapons, L50 Armor, Level 30 Ring
Recipes: L50 Helmet, Level 50 Lance, Level 50 Pistol
Other: Ankle Guard, Evil Stone, Black Gold
Warrior Road (Level 55-58)

Boss name: Guardian Beast
Health:
Elements:
Weaknesses: Light,fire, earth
Strengths:
Drops:
Gems:
Equipment:
Recipes: Great Warrior Stone, L55 Headgear
Other: Warrior Stone, Owar Stone
Zhenmarshou Forest (57-60)

Boss name: Bulbdorados
Health:
Elements:
Weaknesses: Ice, fire, darkness, beast
Strengths:
Drops:
Gems:
Equipment: L55 Rare Weapons,
Recipes: Great Warrior Stone, L55 Armors
Others: Warrior Stone,