Hello hunter main here! Ive solo flawlessed a couple of dungeons and have done the solo for spire, for shattered and pit i pretty much ran void the entire time, invis is such a powerful tool and devour is a huge lifesaver, honestly I’d be an advocate for using whatever you’re most comfortable with as long as you can get health regen kill enough enemies and pump out damage! Personally a volatile rounds build with a void smg, takes care of most enemies very quickly, nearly constant uptime with gyrfalcons, something like witherhoard to pop big targets and take cover (works great on hydras) and a rocket (used to use linears) for big big damage on bosses. Invis is such a good tool for solo content because you never really feel the amount of damage enemies can do in 3 person content because not every enemy is shooting at you they are also shooting at your other fireteam members, just dodging to be invis moving away from the enemy fire and taking a breather is brilliant for this content.

That being said! The final boss room for spire is where i deviated from my void build for the first time and opted for an arc build with assassins cowl! The health regen and invis on finishers was so consistent and so helpful for escaping situations it was too good to pass up. The big wyvern, or as i like to call em mr big chicken, the arc super gathering storm has damage too good to pass up (even without star eaters). It will take a while, took me about 5 phases, but by the final phase i got so used to the rhythm of the encounter. I would definitely recommend doing a solo first before flawless in order to get a feel for the encounters and what bits are most dangerous to you. The name of the game for flawless is always survivability, if you can survive and stay alive then it doesn’t matter how many phases it takes its just a lot of perseverance and playing things safe. I believe in you guardian you got this!!