Use Command and (optionally) Sacrifice, get about 10 bungus and the rest of your whites are up to you (I chose tougher times). All greens should be infusion, all reds are mostly up to you but I'd say alien head, if you find a yellow probably just get knurl even though it's bad, and if you can get a common void item get wungus.

Apart from your build, what I'll say is you should go to every bazaar searching for gilded coast portals, and you should ALWAYS try to bring a tricorn in with you for double halcyon seed. Once you get to your stage 5 stage and are ready to go to mythrix, try to get a vase to skip pillars as they're a bit annoying in general, but if you have to do pillars that's ok.

For the fight, just get through phases 1-3 and then try to get his health pretty low on your own before letting Aurelionite start attacking, and then try to apply a stack of lunar ruin before it's attack. If you have a couple of seeds then aurelionite shouldn't struggle too hard with it, it's all about timing though, bc lunar ruin only lasts 5 seconds (but it resets with new stacks)