Here's a video on how to obtain ALL of the prologue achievements, and more! Links to the specific achievements, in order of when you'll obtain them, are in the video description. I didn't show battles as some are walked through by the AI, and most others are simply auto fought and won. The last one appears very difficult, but my game cut out, and I didn't complete the prologue.
As for this achievement:
1. After the first quest, I proceeded North West.
2. Here, I encountered a quest, that offered a strong magical weapon as one of the options. I chose this option.
3. This unlocked a magic item, which can be equipped in one of the four slots, alongside armor and a weapon.
4. Equip armor, a weapon, a talisman, and an enchanted item (which is what the 4th item was) and the achievement is yours!