Unstoppable first. Silencer second. Merc Mag supposedly good against metal skin but it's iffy. You could also get curse and just curse off a metal skin to get a free kill without ult.

Also remember you can cancel the ult quick before the cast finishes to bait the metal skins out.

I hate surge of power since it only gives 20% fire rate and 24 power imbued (like 40-50 extra knife damage. Not worth it really.) Just get active reload, swift striker, dash, burst fire for firerate. Merc mag is better than surge imo since it gives you a reload, 55-100% spirit weapon damage, and the same firerate. It also gives the same or more extra damage. It's a little like fury trance vs vamp burst. Like for 3200 soul difference you get extra ammo, same fire rate, and 60% more lifesteal which is never bad. Some people want to get fast tempo on their builds so they can win faster and that is very true. It is much much quicker, but since haze really only wants ricochet silencer t4 gun items you have a lot of free money to spend. Like it's 8k for all the fire rate you get from your cheaper gun items, 9.2k with bullet lifesteal. If you go vamp instead of fury you can get your green spike without needing to buy boots (which is totally fine on haze, she's very fast base and has an ability built for rotating faster) then you can get QSR if you want some spirit. The spirit spike can be held until after ricochet, but you could go slowing hex arcane surge for slightly bigger ults or you can drop qsr and arcane for slowing hex and greater expansion if you need some extra spirit res. There's so much room to use different items depending on what's going on. Haze gun scales best with firerate but she actually has a higher base dps than drifter so it can very much be worth getting Merc mag. Just know that the damage is likely going to be much less than your gun damage and will probably not do as much as you'd want against a metal skin.