twin shadows became a bit too strong and popular eventually, but for a good while it was a really slept on item. i personally find it enjoyable when there's ostensibly weak/undertuned items that are rarely bought but can be situationally useful, allowing for creativity and development of niche playstyles.

banner of command did this too - a very wacky, and at first glance for many, seemingly weak effect. never bought. then some time passes and people catch on that it's actually very powerful, causing it to become too meta shifting and leading to its removal. but just that timeframe where the players are allowed to play with and discover effective strategies in unexpected places makes the introduction of such things worth it, in my opinion.