Hey,

It's my first time playing and I'm having a blast with the game. That said, I have a question: I tried to locate the Afterdark society but each NPC keeps giving me a different temple to go to, I visited pretty much all the temples of the city but didn't find anyone, so has someone a hint ?

Just looking online a bit, it looks like the Afterdark Society might not actually exist other than in the game's dialogue. In other words, I don't think you can locate the Afterdark Society. Even if you did, it would not be possible to join it, because Arena didn't implement joinable factions.

(The Mage's Guild exists, but functions solely like a place to buy spells and potions and use the Spellmaker.)

Thanks for taking the time. It's weird though, the player's guide mentions the thieves guild, the blades and the dark brotherhood. The rumors mention a lot of various events too, like plagues, wars, imposter kings or queens, cataclysms, etc... if they are all only flavor text it would be very disappointing. There is still hunting artifacts and monsters, plus the main quest I guess, but the game feels suddenly much smaller.