If you join the Beserkers ( Allies from the Middle Ages) you will join them but as the lowest rank possible called a Cultivator. If you want better weapons and armour then you need to try and get a promotion to a Warrior and you can do this by talking to Ragnar. Before you do, however, you need the meet the following requirements:
To unlock the quest, you need to speak to Ragnar in the Hotel Ruins of Goliet.
You will need to find Gunnar in the Valley of the Damned for Ragnar which is to the west of The Great Lift in Edan. While you make your way there, there are a lot of bandits so try and kill them one by one, luring them to your location and try not to go too far into the Valley of the Damn as there are a lot of high-level monsters.
If you head to the hill to the north in the valley after killing the enemies in your way, you will find Gunnar lying on the ground in his own blood and pick up Gunnar’s Journal for 400XP.
Head back to Ragnar and complete the quest for 800XP more.
To unlock the quest, you need to speak to Cormag in Goliet.
In the quest Cormag’s Solace, you will need to help Cormag with some of his work and will need to report to Born from the northern end of the village which will give you 200XP. Once you have spoken to him, he will ask you to get rid of 15 Gralla Roots for 100XP and then go to the barrel near the wall and throw the roots in there for another 100XP.
Once you have finished, you need to head back to Born and then to Cormag to complete the quest and you’ll get another 200XP.
To unlock the quest, you need to speak to Angrim in Goliet.
You will need to find Zerwas after speaking to Angrim to collect taxes in the village. Once you do this, you will see Zerwas start his work, follow him and stand close to the people he is meeting so you can overhear their conversations. There are three different conversations you need to hear and wait until the money has been taken to Angrim.
Talk to Angrim and choose what to do:
If you tell the truth, Angrim will be in your debt and you might need to kill Zerwas for his betrayal. If you don’t want to lose his support you will need to accept and kill Zerwas after following him until he leaves the village, this will give you 300XP. Once you go back to Angrim and tell him the deed has been done, you will be given 500XP.
Once you have finished the quested above and gotten Jax to level 15 you can go speak with Ragnar and ask him to make you a warrior. This will give you 3000XP and the Magical Fist item which is either fire, ice or poison.
After becoming a warrior you can also buy new weapons and armour from the merchants in Goliet and go onto to become a Paladin.