What is the next step?

Regal, desecrate, fracture and hope for crit, phys damage is fine but crit is ideal. Don't really need to divine for 5% crit, but you can if you want to be 100% perfect.

You can watch Fubgun's mirror bow craft from the beginning of the season for a pretty good method if you're going for a 'perfect' craft, I followed it a week or so ago and crafted a pretty good bow out of it, but it's expensive.

Id say apply greater essence of abrasion for flat phys or greater essence for atk speed, then desecrate and fracture. If it hits the prefix, then apply +3 essence with omen of prefix crystallization

Then you will have t1 fractured % phys and full suffixes. Whittle until flat phys or phys acc rating

Then desecrate last prefix. Might take multiple omen of light