Some cards from the Kaladesh set use energy counters to pay additional costs or buff cards
A Gray Ogre is just abysmal, and while it has a decent activated ability that can make it a 4/4 with Haste, I dont think this does enough to be saved from being a card you cut significantly more often than you play it
Definitely worth the investment
The other option is to take advantage of the direct damage, which is good in its own right to either finish off a damaged character or get them within range to be banished but also works with the likes of cards that benefit from being damaged - such as Scroop, Backstabber - that benefit from healing damage, like Rapunzel, Gifted Artist, or from damage being dealt: like Beast, Relentless.
(It costs less to cast for each artifact you control as you cast it.) 7: For each artifact you control, create a token that's a copy of it