I have an object from the forge and figured the quest was done. However, right after, on the road east from Winterhold, I ran into a group led by a powerful wizard who questioned me about the object and then attacked. This guy was tough and in the middle, I got attacked also by an ancient dragon so that was that with that.

Anyway, I reloaded and this time only had to content with the wizard which was enough.

Question: was this a one off or will there be more 'adventures' due to my possession of this object? Is the quest continuing still?

After finishing the quest, you have a random chance of meeting him. In case you didn't realize, he is Katria's apprentice who stole her work.
He will always turn hostile if you speak to him.
That's it though, nothing more to do with the quest.

OK, thanks. Now that he's dead, I guess that's over.

He also has a named set of Master Destruction robes.

Yeah, I got them, but I am like 21 in Destruction so they don't do me much good.

What are they called please? this just raises a point though about named and unique items in the game, in the midst of all that thrashing about over these items i completely forgot about unique robes, of course there should be, pity they do not have unique enchantments.

They're called 'Taron Dreth's Robes', and look identical to the Master Robes of Destruction. However, their effect is only as strong as the Apprentice Robes of Destruction. It actually fits; he's taking credit for someone else's work, making himself look smarter than he really is. A weak set of robes that looks the same as a stronger set makes him seem to be more powerful than he really is, which fits perfectly with his personality.