have to keep in mind this is a bonus to weapons, which are benefactors of cost reductions, limiting this card to weapon buffs allows it some more freedom than for ash eaters or any other creature. blessings do a 1:1 cost:+atk ratio, but that is for creatures, and also has an equal hp buff to boot. this is purely a +atk card, limited to weapons, a 1:2 cost:+dmg ratio and a 2:5 cost:+dmg ratio, respectively, isnt terrible for a weapon buff. and also you can find creatures with roughly as good cost:atk ratios in the game already, minor phoenixes cost 2 and deal 4 damage, the unupped tempering does the same ratio, but as a weapon, the upped does a slightly better ratio, but again is limited to a weapon.