Since the Moth Miraculous grants no special powers to the user, they would need someone to fight on their behalf.
Master Fu has not stated directly what powers the Turtle Miraculous grants, but he does imply that it grants the ability to heal.
When Marinette wonders how he cured Tikki by chanting and ringing a gong, he states (after she leaves) "Ancient Chinese secret, just like yours", suggesting that this is the power granted by his Miraculous.
Given his extended lifespan (182 years) this could be another power.
He didn't really have a choice in which Miraculous to use, the Ladybug powers exist solely to defeat Hawkmoth powers and the Cat Noir powers are a matched/opposite pair to them.
I'm assuming while the Fox and Bee powers are significant, they aren't what was needed to defeat Hawkmoth and therefore, of no use in this situation.
If hypothetically, Hawkmoth was to be defeated, I doubt Marinette could go back to an ordinary life.
It wasn't addressed much, but it was suggested in one episode her superheroics involve more mundane activities, because she keeps missing classes for this reason, in particular, a police helicopter was about to crash into the ground and she used her yoyo to spin a web around it.
So, she'll always have something useful to do, even if it isn't fighting evil.
My impression is that for situations that don't involve Akumas, tWahey don't need powers other then their enhanced strength, speed, agility and their enchanted weapons. Ladybug also has the ability to wallcrawl.
They just have to think of ways to use all of the above to solve whatever problem they face.
That is why I don't believe they have or need any more "hidden powers", since they already have the powers they need.
Watch Syren
That might be a sadistic thought, but he can kill or destroy the akuma with cataclysm. Hooray evil!
Ladybug is creation, so she purifys the akumas. cat noir is destruction, so he would corupt them. Le Paon is going to be able to make alies for the villans, so maby cat noir will be able to defeat them.
Akumas are corrupted beings already, why needed to be corrupted again? They would be destroyed.
so cat noirs power would do the oposite of ladybugs, ladybugs takes away powers, so cat noirs would make them stronger, like darkblade's wall that turned people into knights, would cover the whole world, not just paris.
I think that even if Ladybug would be akumatized, he could just take her Miraculous off or use Cataclysm on it because he did that with the Bee miraculous and later everything was set good. Both of these options would lead to Ladybug revealing her secret identity.
If he destroyed Ladybug's Miraculous, nothing would get fixed since her Miraculous isneeded to fix everything.
Also for future referance, try to avoid commenting on forums that haven't been commented on for 2 weeks.
cat nior is destruction
ladybug is recreation
so in a sence cat nior cant purify he could probably destroy the akuma tith his staff
but ladybugg always purify
but it is kinda sad though that adrien loves ladybug and marienette loves adrain but she neve asks him out or it would ake the story progress better if they know eachother why dont they yet tell eachother who they really are it will gain some really akward moments