The past 5 zodiac rings ive found on my seasonal barb all rolled with the same 4 primary stats and every time i try to reforge it i get the same stats too
That’s because the ORotZ has four guaranteed primary affixes, one guaranteed secondary affix, and one random magic affix so you’ll always get CDR, AS, CHC and RCR as primary affixes. That’s why it’s generally advised to have this ring in the Cube rather than equipped, as other rings you could equip (e.g. CoE or BoM) can have more useful / offensive affixes.
Maybe he got a nice secondary like lightning res?
That’s just how Obsidian Ring of the Zodiac rolls.
A very, very large number of items in Diablo will always have certain stats depending on the item. The biggest example is that every class-based set chest/legs will always have the maximum number of sockets. Additionally, not all items are equivalent in terms of stats - Some items can roll 5 primary stats instead of the standard 4(Pig Sticker), and other items have stats that’s not available on any other similar piece (Witching Hour, for instance, is the only belt in the game with CHD and Attack Speed, making it a strong offensive belt for builds that don’t use an offensive belt slot)