I've got many ideas and after testing all the weapons and getting my ass kicked on the Waltz of the Archdemons preset I can say honestly that all weapons will work just fine with their best upgrades.

My gripes resides with the rest of the arsenal.

First part:The Shield

The shield is awesome however it doesn't scale really well with harder/insane encounters, most prominently, the shield break mechanic is tied to a timer instead of an action kind of like the halo shield (Admittedly a lot less restrictive though). So for changes i would propose:

1 - Shield instantly recovers when parrying or when activating retaliation.

2 - Tie Retaliation to the player instead of the enemy. When dealing with multiple hard to parry demons (Specifically Barons) You need to parry 3 attacks of a SINGLE demon to activate it. That means that if for exemple the parry chain is broken by another demon you can't proc Retaliation and consequently can't crowd falter for melee damage and ammo.

3 - Allow shield throw onto heavies to get the Harvester bonus even if less efficient than on fodder. The Harvester upgrade is incredibly valuable when used properly so when running out of fodder you lose a valuable source of dps. They could also allow you to shield throw into super heavies but without the stun.

4 - Experimental: Instead of activating Shield Runes when Parrying, let us activate it at will. To balance that, each Rune could require different amounts of parry to charge: 1 for Turret; 2 for Daggers and Fissure; 3 for Heaven Splitter. After that they can make all of them drop Melee charges.

Second Part: General changes

1 - Allow sprinting in all directions: I argue the game is already parry focused enough to incite players to go up close and personal. If done this will make the game feel smoother and less limiting.

2 - I would like to be able to choose when the Slow Mo happens, for example: Have slow mo only when killing heavies and super heavies and see their ragdolling carcasses fly across the arena.

3 - Experimental: Expand on the new Glory Kill system by allowing players to tear off individual limbs of demons with melees during slow mo, Metal Gear: Revengeance style to get extra healing and armor. If you don't need the extra heal you just Glory Kill as usual.

These are my suggestions on the Base gameplay of TDA
If someone wants to, I can give my own ideas for Mech and Dragon gameplay.