Gun ideas:

Frickin' Lazor: Fires a constant laser like the one fied by roarmulus twins, but shorter range. Deals low damage multiple times per second. Lazer starts out weak and heats up over time, causing more damage over time before eventually overheating - if allowed to overheat, it can't be used for a reload period. It cools down normally over time if not in use and can be maintained at the highest damage output with careful use. An alternate version causes Fire at maximum lazer heat, has lower damage, might be elemental (but we have far too many elemental status guns now). Charge attack only charges during reload period, fires a lazer at maximum power for half the length of time a clip lasts, but also pushes enemies back.

Higher * ratings increase clip size and range.

RPG: Fires missiles like those seen through the Ironclaw Munitions Factory, 2 per clip. If the attack button is held down, the missiles home in on the mouse cursor. The charge attack fires a homing missile which automatically targets the closest enemy to the knight, but causes no more damage. Typical use would be firing the first two missiles, guiding them to the target and then releasing the charge attack, repeat. Alternate version can be shadow damage and curse because both of those need some love.

Higher * ratings increase blast radius or time before the missile automatically detonates.

Bomb ideas:

Tripmines: Only explode when an enemy comes into a range equal to half it's blast radius

Remote detonation: Explodes when the user places another bomb.

Both bomb ideas can be used to remake all of the old bombs, making this an easy way to populate the game with more bombs.

UV ideas:

Additional [Type] damage, but reduced base damage: Low - 2.5% of the weapon's damage is replaced by 5% [Type] damage, e.g. 100 normal damage would become 97.5 normal damage and 5 shadow damage. Scales linearly. The weapon causes additional damage to monsters the new type is weak against, but reduced damage to those it's strong against. Essentially a damage bonus to two families at the price of a damage penalty to another two. Always increases damage against anything neutral or weak to the new element, reduces damage against the last two families.

Increased chance of status effects - Increases the chance of a weapon causing a status effect, if it can.

Reflects damage: Low - Deals 1 normal damage per quarter-pip of hp dealt to a knight to each enemy adjacent to that knight. Effect scales linearly, up to 6 damage at Maximum!. This effect essentially scales itself to each tier. Could also be used on shields, in which case it reflects the damage they block. Doesn't reduce damage to the knight in any way.

Detonates on Shield Break - When this shield breaks, causes an explosion with a blast radius/knockback equal to the same * in the Blast Bomb series. Damage is dependent on UV level + * rating. Damage type could be the same as the shield's resistances, or just Normal.

Chance to cause [Status effect] on Shield Break - as above, but instead of causing damage and knockback the explosion has a chance of causing the status effect listed.

...I have to go eat, so I'll update this with anything I can think of later.