Quote from italofoca »I think that one also needs some rework too. +1/+1 and first strike is not really great effect when the opponent knows it's coming.
You might have a point if it was sorcery speed, but effects like Seal of Strength are very relevant since it changes combat math. You can still swing your two 2/2s past their 3/3, for example.
A name change wouldn't hurt, though.
I think all of these are great. As with any cycle of effects-based-on-color, some are going to be slightly preferable to others.
Though in a vacuum I'm left wondering why these are artifacts instead of instants, it's not hard to justify it in an artifact-centric or permanent-centric set, or in any set that wants a higher permanent count, like if revolt or ascend are in it.