This is a terrible upgrade. The level zero version is great. It is a weak dynamite that doesn't hurt you or your allies and includes an optional elusive at the end. I've done 14 damage with the level zero version.
Sure, this can do a lot more damage with the upgrade, but the test will be much more difficult and it is only better in boss fights. I fear this was priced at 5xp based on what it could do, not what it will do in 99% of scenarios.