I want to like it, but it's just not good enough. The resource, deck slot and action cost is not trivial. Getting it out early enough for strong value will likely delay playing other more critical assets like weapons or allies.
The Good:
- The effect lasts the whole round, so you can support your allies with it.
- It's a free, fast engage on aloof enemies, which are often non-Elite and fragile.
- You can wail on troublesome elusive enemies like Zamacona.
The Bad:
- Alert and retaliate are most worth cancelling on big scary bosses, but this has the all-too-common non-Elite clause.
- The bless has to be revealed at your location, so your bless engine better be really humming.
- Playing it in the heat of battle is almost never worthwhile unless you're absolutely drowning in aloof/elusive enemies.
Like Grievous Wound, this is a very narrow tool that tries to help with elusive enemies, but is still weaker than brainlessly hitting hard. Like Absolution, it's not a strong enough payoff to motivate a bless build unless you were already doing it.
If it were free, fast, or effective on elites it might edge into being usable.