Second, this card in particular is so cool
You can cast them early to cash in on their ability, but youll then have to wait to get the Overlord later on as a creature
It also has a passive ability that makes it incredibly safe to use: As long as The Aetherspark is attached to a creature, The Aetherspark cant be attacked and has Whenever equipped creature deals combat damage during your turn, put that many loyalty counters on The Aetherspark. With the right creature, you could be drawing two extra cards a turn, or you could simply make it easier to ramp up its ultimate ability
Its certainly one of the prettiest cards available in Temporal Forces, but it manages to offer a lot of competitive potential with Prism Edge, too
And which should win really depends on whether you value the impact back at the time or their longevity
This Common card is no ordinary bug