Why exactly throw in phsycial traits for the element fusions. There wouldn't be any beings to have them
EDIT: Nevermind, I checked
Well, here's some of my ideas. Keep in mind most of these were decided late at night and just so I had one for pretty much every element covered.
Acid: A weak irritant covering their skin that can cause burns with long exposure.
A bit too specific, if you ask me.
Kinetics: Perhaps just more agile/faster. They could also be harder to stop, like they build up momentum faster.
That could work too, I really didn't have any ideas set in stone when it came to Kinetics
Sulfur: Breathe easier in dusty/sulfurous environments?
Gold: Good with money They can quickly calculate value of objects perhaps, usually businessmen
The "calculate value" thing sounds good, maybe Matoran of Gold could be Pawnbrokers
Silver: Can amplify elemental beings they retain physical contact with
In the sense that Silver is highly conductive? A bit too farfetched
Mercury: Faster than other Matoran
What exactly is the reasoning behind this? Forgive me, I'm not very familiar with mercury
Tar: Move easier in tar, quicksand, etc.
That sounds reasonable
Ghost: Can create small, shortlived holograms, though Dr. O's idea sounds good too, maybe even better.
Keep in mind these are supposed to be minor physical traits, not extra powers
Fungi: Could help natural fungi grow
Blue Energy: Passive energy charge
Could you elaborate?
Glass: Better eyesight if crystal doesn't get that, or possibly a slight weakening effect to solid substances?
Why not take a page from canon, if both Earth and Stone have enhanced strength, then why couldn't glass and crystal both have sharper eyesight.
Storm: Can sense weather changes, or weak electric charge
Twilight: Can see better in strong light and in the dark
Obsidian: No ideas
Cloud: can generate a weak fog
I refer you to my comment about the Ghost ability
Swamp: Can possibly turn dirt to mud with long physical contact
I'm not sure, actually
Vacuum: Breathe easier in low-air environments
Steel: Sorry, nothing that isn't covered by any of the metal elements
How about it takes longer for their armor to get dirty, stainless steel of sorts
Wood: "Green Thumb"
Already covered by Plantlife. Although, I haven't seen climbing ability in any Matoran so far, how about that?
Quicksand: Can walk easier in quicksand or possibly create small amounts
Again, the quicksand creation thing is more of a minor power than a mere physical trait
Dry Quicksand: Same, I suppose
Poison: Resistance to poisons
Magnets: Weak magnetic field that can be slightly strengthened or weakened at will
How is this even an additional element? Isn't Magnetism and several metals already elements?
Anti-Gravity: Not affected as much by heavy objects or strong gravity
Same as above, how?
Salt: Always covered in thin film of salt.
Or they could eat more salt without growing thirsty or sick
Copper: Can channel electricity, sense charged wiring,
At risk of own health, perhaps?
Electromagnetism: It's hard to come up with something not already covered by Magnetism, Electricity, Magnets, or any of the Metals
Electromagnets: Really. Ditto ^
I refer you to my comment regarding magnets
Rubber: Can't channel electricity, flexible,
Probably more like resistance to electricity, they aren't made of rubber after all. Flexiblity sounds plausible
Plastic: Sorry, no ideas...
Blue Fire: Resistance to superheat/burning
Like an extreme version of regular fire, right? I'm down with that
Frost: Resistance to supercold/frostbite (if it occurs)
That sounds good
Radiation: Passive radiation sense
Oil: I'm at a loss
Natural Gas: Can sense dangerous gases
I can't think of anything better myself, really
So, how's that?
Avaliant effort, I apologize in advance if I come off as snarky, it is not intended as such.