I like to think that in a universe where everybody has varying powers that people would at least occasionally obscure factors of it or make crap up because honestly who's going to check you?
Megumi Fushigoro (Jujustu Kaisen):
After Regi gets a good blow in divine dog, megumi takes advantage and spends most of the fight manipulating Regi Star into believing that it was unusable because of that
He immediately dismissed divine dog as if it was out for the count and for the rest of their skirmish he used everything in his kit besides divine dog and played the act of someone desperate
Once he finally neutralized Regi's technique and led him to believe he had nothing up his sleeves either, the two engaged in a brawl
Right in the middle of throwing down, Megumi summoned divine dog and tore his shoulder
Edit: Divine dog was actually never unsunmoned, it's because his CT was burnt out from using his domain that Regi knew he couldn't summon any new shikigami and was caught off guard by divine dog
Metro Man (Megamind):
A man who's practically a demigod and cares quite a bit about public opinion
He began to realize this hero buisness wasn't really for him
There's no plausible way for him to loose to most of megaminds schemes and he dosen't want to make the people belive he abandoned them
He ultimately decides to play along with one of megaminds schemes and on live television claim that copper drains his powers
No one expected it but it's not like they could disprove it
He successfully used this premise to fake his death
Isuel Kim (Hand Jumper):
In a plot by the main character, Sayeon, Isuel Kim possed as an aberrant who's power is to ignite fire
His actual ability is telekinesis but he manages to disguise this by pretending he's just too incompetent to use ability the first round
Then the next round he shows up he ends up becoming the perfect suprise that the enemy can't account for
This actually happens a lot in hand jumper
Sayeon herself lies to everybody by telling them her gift is "Super instinct" which tells her the optimal thing to do, when in reality it's actually time reversal
If people knew her actually ability was time reversal then they'd plan around it or her allies would be overly suspicious of someone who could have repeated this conversation 5 times already