Bisharp costs 400 Pack Points to craft
The performance by itself isn't that strong, and dragons have the same material designation and level, so the effect is more useful over there, but the ability to revive from true flames is a big advantage, and if you can successfully activate your own effects from a mass deployment
In the case of the former, you can even sacrifice Boromir in a key moment if you know that someone is holding free interaction that can stop someone else from winning the game
You need at least 7 mana from other sources to net a single extra mana from the Cube, and its usually easier to find an infinite mana combo using ordinary mana rocks than it is to turn this into a reliable engine
Oh, and before we start, this is how I stay connected while Im in Japan quite honestly theres no one else Id go with
The same risk applies to blocking, but the potential to become a big threat might deter incoming attacks altogether