Flash freeze and radar freeze enemies, buying the time for perfect swing and charge, then blow up the entire screen. Scoop up exp, rinse and repeat. Tricky as the wait time gets scary but the audio and visual ques of perfect swing and charge make it pretty easy to manage.

One shot the entire screen even an hour in, lost shield and akimbo 4-5 times and managed to get it back every time even after being an hour into the run (except the last when I died of course)

Giant blade- Increases Damage Significantly, especially for early game
perfect swing- Damage, width, range; scary to wait the two seconds to swing but the pay off is great
rampage- more damage, you won't miss when you hit the whole screen

Main/Damage
Bulk Rounds
Whole Tree, damage, range, the pierce ramps up the damage to well into 4 digits and scales great as the density increases in late game.

Quick Draw, Ballistic Tip-Some attack speed and attack range, multishot might be ok but I didn't want the damage decrease

Shield Barrier
Boost, Flare and Akimbo- Boost and Akimbo are the main priorities but flare is nice later for safety, Boost for the damage, Akimbo so you sweep the entire screen front and back

Shrapnel
Everything but Death Row;
Doom and Calamity are huge damage and range increases that you'll be able to replenish with each swing, the shrapnel is great AOE as it gains the damage and range you're building up. Death Row might be ok but the great sword already swings slow and the fire rate decrease might get you killed

Wildfire
Most of this is pretty nice for AOE and blowing up the screen. Didn't manage to get much of this is my run but definitely felt good with what I had and would be better with even more.

Electicity
Can be good with chain lightning, probably don't need much more than that. Shrapnel will get boosted by the lightning effect so pretty nice damage

Utility/Safety
Concealed Fatigue
Bottom Row Only, top row doesn't play nice with the flare from shield barrier. Great damage increase that goes well with the shield flare

Gleam
Entire Tree is pretty nice and flash freeze is fantastic for safety as you'll be standing for at least two seconds before swinging. The freeze buys that time and the rest makes it a larger area

Slowed Projectiles
Bottleneck and Meet your Maker only, boosts damage, less dodging of projectiles so you don't lose your shield

Spotlight
Bottom Row only, the radar freeze is fantastic for safety to buy time before you swing

Swiftness
Whole tree, exp engine, charge is very nice as if you can wait the extra second it boosts run and gun which is a pretty good damage boost as well as an escape if you need it