Divinity:
Name: "Team Effort"
Cost: 250-350 
Description: Minions complete missions 0.1% faster per Minion level.
My reason: A great way to gain Minion levels and Slayer Points faster. Since there are only two Divinities that speed up the Minions' completion rate(by 20 and 15% respectively), it's good to have at least another one added. The high cost of divinity is to make this balanced.
Dark Divinity:
Name: "Quantity Over Quality"
Cost: 350-400
Description: Minions complete Missions 50% but they give half the Slayer Points.
My reason: Again, it's good to have another Divinity that speeds up the Minions. This time by a whopping 50%. But of course, this comes with a price: Half the Slayer Points. It's a good Divinity if you want to grind more Divinity Points.
And while we're at it...
Name: "Quality Over Quantity"
Cost: Same as above
Description: The opposite effect of the above Dark Divinity.
My reason: Good for grinding Slayer Points.
I'm open for changes.