Invoker had it’s shines of glory, with the most popular being the Miracle- era, where everybody who was anybody knew how to play the hero, and it was not uncommon to see him 10 games in a row. He got heavily nerfed after that era, with multiple patches being catered to weakening him.
He is now back in meta, however, and we are finally seeing this hero make a comeback in the pro scene. His skills a very diverse and adaptable to say the least, being able to play almost any role in the game (weakest being support); and makes him a very difficult hero to deal with if not properly counterpicked.
Back then QE was the only way to play the hero, normally built with medallion, it normally crushes any opposing midlane heroes except for a few. Nowadays, both QE and QW are very viable in gameplay, so can definitely see both coming into play most often in modern gameplay!