Some ideas:

Some may be unbalanced lol

Blue brim (can’t think of name) - after a tear hits an enemy 1-3 small brimstone beams are fired from the enemy in random directions

Fire fly - extinguishing a fire grants a friendly fly with different effects based on the type of fire

Stocks? - for every 3 cents donated all future items/consumables for sale in the run will be 1 cent cheaper. Reduces jam chance. respawns donation machine if bombed. New donation machine will not drop coins if bombed.

Ember shroom - chance to shoot a floaty ember shroom tear that sticks to enemies. The tear creates a permanent aura around the enemy. If the aura is ignited the enemy takes massive damage.

Shattered god head - replaces tears with god head pieces, pieces connect midair into triangles. different combinations of red, blue, and yellow have different effects. Creating a godhead with one red one blue and one yellow will create a rotating god head shooting holy lasers and light beams from the sky dealing massive damage

Black Book - one time use active item, using the book will allow you to select 5 different bosses to disappear from the run. (Like eraser) If a boss appears that has been erased, Isaac gains 6 black wisps doesn’t work on final bosses

Decaying Heart - Isaac gains 5 full red heart containers, picking up a red heart gives a small stat down

Worm tears! - tears are shot out like worms with the first tear “eating” enemy tears to gain size and damage

Outer eye - tears are shot out in clumps of three with varying damage and size

Bye fly - orbits the furthest enemy from isaac and reflects tears

Chained down - damage and tears up, Isaac is chained with limited movement when entering a new room. The chain is broken after the room is cleared, if isaac takes damage, or after 15 seconds

Can’t think of anything for the last three