When you are talking about Hunting banshee oskill for UHC you have to get
Darkfeast
Darkfeast
Goedendag (Sacred)
One-Hand Damage: 53 to 54
Required Strength: 574
Required Level: 100
Item Level: 105
(Paladin Only)
Strength Damage Bonus: (0.18 per Strength)%
+(0 to 2) Projectile to Hunting Banshee
+(50 to 200) Spell Focus
+50% Damage to Undead
+(30 to 50)% to Cold Spell Damage
-(10 to 25)% to Enemy Cold Resistance
+(18 to 30) to Hunting Banshee
+50 Life Regenerated per Second
Total Character Defense (30 to 60)%
+50 Life after each Kill
Socketed (3)
with +2 Missiles and decent other rolls to make it work good. with those 3 missiles in total you can farm dunc and fauzt okish. When it comes to bossing the autoaim is either helpful (Belial, Kabraxis,..) or can screw things up (Astrogha, Xazax,...). Fun oskill to try out but nothing to powerful.
As for the Druid: Hunting Banshee and Stormclash (skill was renamed from Stormfront) are top tier Caster Druid Specs. When you are struggling with Stormclash against bosses you should work on your gear (pierce, sd, synergy from EF/energy).
What clvl are you? 5.2 k seems low when you are >=125 already.
With decent gear you should be able to reach 150+ pierce with like 9-10k Stormclash damage @4 Bolts with all the 125 charms.
When you can't make Stormclash work you won't make Hunting Banshee work.