This is my first guide. Feel free to comment for better advices.

This is the DarkKnight [Harrow] build for Squads.

It is a Pretty simple Build. you Try do Heal up youre mates with Penance and Thurible.
With Pillage you can Cleanse all Status effects from mates ands you and get extra Shields.
While Covenant is youre Invul Button for the whole team in Affinity Range. Use it to get more Crit Dmg or Rescue the team from an wipe and get more crit dmg.

You Dont have to use Pillage. You can use Condemn. Then you dont have a cleanse for status effects but an nice CC. Its up to you, which you prefer more in playstyle.

You change [Augur Secrets] with the other Augur mods, [Stretch], [Natural Talent] or a Umbral mod. Its what you Prefer. More Range, Duration, Health or Cast Speed. (but for the Umbral mods you need one Umbra Forma instead of an normal one.)

Arcane Mods Are Playstyle Preferred. (I dont really know at the moment which are perfect for this build...)

My english is not the best. So please let me know how I can write the guide better for better understanding.