Who would have thought a cloak-like ability on a weapon? Genius!
I really like the idea of a cloaking device and since Cloak already did that in spade for everything, a specialized weapon that target only your creatures seems the second best. But I feel like it is a bit too powerful since it granted an ability to your creature which something that has never bone done before by a weapon. Granted, it is only cloaking every other turn but being able to spam this on a full field is a bit OP in my opinion.
What I would do instead is change the wording so that it would read like this :-
Weapon. Deals 6 Damage.
: Target creature is invisible for a turn. Cannot target the same creature next turn.
Also, the name is a bit misleading, the weapon itself is not hidden, 'sup?