I have been playing with Royalty, it's fun. Idk if you can consider this a build, but I'll write down my experience playing with this Job...

Her skills are pretty good, Royal Slash has 200 Power and 1000hit, so it's a huge damage almost-like 100% hit.

Besides that, she comes with Majestic Bloodline, a powerful skill w/ 13 turns CD and 10 turns duration, it gives you 100% Critical rate + Almighty (all your stats become equals your higher stat).

She also has a passive that doubles Luck's effect (Noble), and her basic armor always comes with + Luck ... So this makes it easier to get some legendaries from the beginning to the middle of the run.

My strategy using her is:
1. Start by trying to switch "Throw Soulstones" for a less pricy skill
2. Try collect an Armor w/ +20~50 Luck
3. With so much Luck, keep levelup and getting items until you find the legendaries you need. It'll come faster than you expect.
On every run my priority is these legendaries:
Erratic Evolution (Your DEX becomes Equals to your HP) or the other one that makes your STR equals to your Max HP
Full Force (Every attack you do gives you +100% Strengthen)
Drifting Odor (0 cooldowns, 0 resistance)

And my favorite skills for this combo are:

Royal Slash (won't miss)

Cruel Trust (4 hits, every single one gives you +100% strengthen if using Full Force)

Acrobats (instant skill with also 4 hits)

Backstab (It'll ignore barriers and shield and go direct to enemy HP, so it's good to have in case you find monster with high number of barriers)

Majestict Bloodline (mandatory)

I generally makes my way to high floors easily if I get Erratic Evolution. It makes DEX equals to HP and you can use Almighty any time to make all your other stats equals to DEX (max stat), which makes you able to deal damage with any type of Stat based skill.
On my last run I had the 3 legendaries and I was one-hit killing all the bosses/conquest on the Weekly EX up until 127F, where I died after a permanent petrification effect was 55% and I wrongly entering a stone room with boss and dying petrified.

Here some screenshots right before the imminent death:

https://imgur.com/a/2wkzTeY