The vengeance pickaxe is a cool mechanic, the problem comes in with packs that have disenchantment abilities like MFR's disenchanter. The ability to move the fortune X to a non vengeance pickaxe is problematic. This isnt a problem with evilcraft persay but if the enchantment was a specific enchant instead like "Fortunes of Evil" and basically did the same thing as Fortune X but only worked on the vengeance pickaxe it would easily prevent this sorta thing.

Please include the AoE part too! I would love to use this on even various weaker pickaxes.

I really need to work on the Vengance Spirit balance though, as currently it spawns on average every other block I dig, there's no danger if it's expected, if it's 1/100 blocks, you'll eventually drop your guard and feel secure, then out of nowhere an angry Vengeance Spirit spawns! (Better hope you brought your ring!) I would totally use this on my lower tier pickaxes, as well as my (Magical Crops) Unbreakable Pickaxe.

I'll think about this.
An alternative would be to make this new enchantment also apply the spawning of spirits to the pickaxe.
You could then still place this enchant on an unbreakable pickaxe, but then it would at least have the same bad effect as with the Vengeance Pickaxe.

That could be cool!

As noted elsewhere, as of 1.8 the anvil won't let you apply more than F3 to vanilla tools, and IIRC Thaumcraft tools as well. Splitting off the enchantment would also let you rebalance the drops -- it gets a little silly for some ores....

Suggestion by squirerl killer: Move ability of vengeance pickaxe to a new enchant, which can also be categorized as a 'bad' effect from the blood chest.

It's worth noting that with random spirits occasionally appearing, that "bad" effect is fairly exploitable.

@MentalMouse That's the whole idea of it ;-)

Oh, well if it's on purpose....