One thing to note though. Your current wording would imply that this card will deal less damage regardless of who has fewer hit points. That means if you should fall behind your opponent this card would start doing less damage, creating a downward spiral... If this is the case, then a slight damage bump may indeed be in order.
Conversely, you can can have the 10 damage be the center and have it start gaining extra damage if you are behind in hp. This would be a very valuable card then.
It is true that if you have less HP than the opponent, this spirit also has a smaller attack. But Aether has other cards that help solve the problem
e.g. Dimensional Shield + Immortal creatures can reduce the HP difference and then let your spirit deal a huge blow. You can also use a Lightning to boost the spirit damage greatly if the HP difference is small enough
Or you can simply use Adrenaline to make use of the low attack (see below for explanation)
As OT mentioned in another post, this card can act as a tiebreaker, and I think this card would bring more variables to the game so I'm not gonna change it except a possible cost decrease
But what you suggest is also a good idea. Maybe this idea can be used in a sister card for this ?
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I forgot to mention the effect of buff cards. If you use a blessing on Resonance Spirit, the spirit will do 3 more damage all the time regardless of HP difference.
It is also worth mentioning that, the attack of Resonance Spirit is changed
at the end of your turn (Similar to Scarabs' HP). So if you use Adrenaline, the attack of the spirit won't change at each attack.
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How does it round? You missed 256.
The attack would become 1 | 3, as you can see the HP difference required to furthur reduce attack by 1 doubles after each reduction of attack.
Minimum attack is 0 but I don't think it is possible to achieve this value
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I'm in urgent need for an art for Crucible, any help ?