Shadowverse

When the Omen was first released, I tried including one or two copies in my artifact deck, and it worked reasonably well, but then I removed it – probably because of the bricking.

There's no need for the "Deus," moreover – it almost caused me to lose a couple of times to Shadow.

The worst tempo vampire. Although, on the other hand, Ward and "can't be targeted" should help. I was also thinking of crafting it, just to try playing with it.

It's just that a 4-4 Ward for 9 power points is extremely weak; there are a million ways to destroy it and attack the hero in the same turn. It's like those Haven players spamming the amulet with Barong and thinking it will save them. And by the late game, people will already have an Annihilator Sorcerer with 15 charges, while you're skipping a turn to deal 4 damage to the hero or, even worse, 4 damage to a follower.
But the legendary card does have potential to fit into some decks, if not now, then later, so the dust invested in it will probably be useful someday.

As it is, though, in terms of power level, this tempo card should be an epic-grade card costing 10,000 dust. This legendary really needs its cost reduced to eight and its damage buffed by at least 4, or it should deal 1 or 2 additional damage to the hero with its acceleration.