Warlock Gear Help / Dragons + Critique of build

For my iOS Warlock build:

Bone * 6 (Lego) pendant,ring,gloves,helm,sickle,pants (all dark except for Helm & pendant)
Esgaard - Pauldrons (epic) & Belt (lego) (both dark)
Night - Ring (Lego), Cloak (epic), Boots (epic) (both dark)
Bloodfang - Shield (dark, lego) ← plan to replace with something.

Spells: Tentacle Slap, Channel Dark, CloudKill, Dark Firebolt
Minions: Pussbag (Lego), Kittiliche (Lego)

I do well in PVP, finished lvl 100 skirmish & a few 100 dungeons.
I want to improve, but don’t want to waste mythic runes if there is a glaring problem.

Also— how should this change for Kingdom defense?