Armor is what is going to protect you from a monster’s wrath. Armor boosts your defense well above its natural 50, which will allow you to take a few hits and give you the safety that you need to go embark on quests. Armor is very versatile.
Complete sets will give you not only the look of the monster, but also sets of skills, and elemental resistances and weaknesses that match the monster. For example, a full set of Jaggi armor will make you incredibly weak to fire, just like Great Jaggi is weak to fire.
Mixing and matching sets can offset this, and provide an incredibly high level of customization and fine tuning.
Unlike weapons, you cannot ever upgrade your armor using monster materials into a different piece of armor. But you can increase the defense slightly through odd items called Armor Spheres. Acquired as quest rewards and from mining nodes, different Armor Spheres will upgrade your armor.
To max out an armor’s defense, you will need Divine Armor Spheres , which are incredibly rare and only come from high-level G Rank Expeditions. Just pump in up to Hard Armor Sphere or so and you should be good, however.
Only the hard, raw defense will be boosted. Elemental weaknesses will always stay the same. Remedy this by eating for elemental resistance at the open-air kitchen run by the Street Cook.
No matter how pitifully low your elemental weakness is, a food skill that boosts resistance will always boost it up to +3. Utilize food skills to your advantage!