This is really strong when you can cast it, but the problem is even when you do, you...might draw your entire deck in Limited
Play the card late game right before you want to swing out for lethal damage or activate it in response to someone blocking too sparingly
They all do the same thing, and are functionally the same card, but that hardly matters - Final Fantasy and Magic mega fans are going to want to have them all to display in a pretty binder
As such, framed alongside effect text like Destroy all black creatures and said black creatures being referred to as foul beast[s] in the flavor text, it paints a brutal picture that reminds people too much of real-world genocides
Then next turn gives two counters, then four, and so on exponentially
The best part of having your Shadowspear or some other equipment attached to Shimmer Dragon is that when it taps to attack - the equipment does not tap with it