Confirming it still only costs 1 charge for multi-hitting.
If Blessing receives further scaling, its base should be lowered. Currently it is pretty strong, since even basic attacks can procc it more than once if you have Sacrament or Enchant Fire (this one not confirmed, but mostly likely works too).
I am almost level 73/12, I am going to get Sadhu later to see if his basic attack will procc Blessing three times (4 with Sacrament)!
Probably will, unless Sadhu’s 3 hits are only visual and coded as only 1, like Catar Stroke…