You need to change the text to... Pay 4 life: Destroy target creature blocking or blocked by equipped creature.

On the cards, i would love to know if means hybrid mana like Beseech the Queen :)

Oops. Yes, thank you.

And yes, pay two mana or black mana.

Heh. And now the feature goes up that makes Veredictum's question obsolete :)

Ah, cool, thank you!

And just because you'll probably be pleased: you might like to know that the card-rendering engine's support for coloured artifacts is in large part due to the fact that your set is up here and has cards like this. :)

­:) Thank you :)

I was very liberal with coloured artefacts on whim as several just felt natural like that (they could have had coloured activations, but the dual mana cost feels like it fulfils the "not better than colours" mission of artefacts) and it's a mechanic which can add something cool to the set without a lot of mechanical baggage. (The same for scry, wither, etc, even though I suppose there normally wouldn't be so many mechanics repeated a little bit at once.)