Need help building zelgius

I don't have a Zelgius but I used to use BK in Arena. The heavy blade + warp + bond skill is a wonderful idea, but do remember that Zelgius with speed bond skill only has 38 speed, pretty unreliable to double many units esp other fellow reds imo. Bold/Vengeful Fighter is much much reliable, and free up other skill slots for more options such as armor boots seal in mixed team. I personally prefer Vengeful Fighter as I run Armor Emblem usually so it is easier to stack ward armor buff, and unlike Grima and W!Tharja, Zelgius actually has the speed to avoid doubles to utilise the skill and still fire off Black Luna everytime.
Dorcas or Adult Tiki? Who do you use more? Dorcas seems like a good colour coverage for Zelgius tho.

I also have a +atk -res Zelgius, heres the build I personally use. Atk/Spd bond w/ Warp Powder seems like a really fun build actually, but he might not be able to double very reliably. Heavy blade is just nasty paired with Black Luna though, so you should totally do that. If not you could always do the Bold Fighter + QR3 Seal combo so he doubles in both phases. But Zelgius is super versatile so just consider your team comp and play style and decide based off that :^)

Also Dorcas and a!Tiki are both decent users of Warding Breath, so it just depends on their skill sets and usage I suppose.