Nuro's Harp - Buff + Rework

I've always loved the thematic idea of Nuro's Harp, yet it's remained unchanged since 2.5 despite multiple leagues targeted at buffing bows.

So here' another idea to fix it. The concept is designed to fit into its flavour text:
"Night's Frost Becomes Morning's Dew
Darkness Cleansed, Pure and New"

15% Chance to create chilled ground when you freeze an enemy or hit a rare / unique enemy.

Chilled ground effects created while wielding Nuro's Harp have frosty or dark musical notes rising from the surface.

Create Consecrated Ground when you shatter an enemy or hit a rare / unique enemy with a 15% proc rate.

Consecrated ground effects created while wielding Nuro's Harp have colourful or golden notes rising from the surface.

Grants 'Herald of the Dawn' Herald skill (insert better name here)
- Enemies on chilled ground created by player take extra base cold damage from all sources (insert balanced damage here)
- Allies on consecrated ground created by the player receive a buff to attack & movement speed, buff lasts 2-4 seconds after leaving consecrated ground

Both effects scale herald effect.