Before she amps, she's going to be toasted most likely. Luck just needs to think to blitz someone who previously massively blitzed him and could turn to a mush with one hit. The reactive power level he has allows him to greatly improve in battle within moments, including speed, and he even adapts to his opponents speed/fighting style to surpass him. Reminder, Luck has more than 1 speed amp. Sayaka is not reacting to him. He blitzed a guy who is MFTL who earlier blitzed him and made him praise Luck's senses and combat capabilities. And he has true flight and immense maneuverability, it will be even harder for her to even reach him.
Magic crystals exist in Black Clover verse. And Luck has dealt with them, even destroyed one. In their verse everyone has their own source of power, mainly grimoires. He will eventually after some time start analyzing what's her source of power and why is she immortal. The crystal could be the only answer.
She's not reacting to him. A MFTL guy with light years more experience than Luck who earlier slaughtered him to the point when he went from tip-top condition to near death state couldn't react to him. His moves are like teleporting and you can't see him, then he's behind you and kicks the hell outta you, or paralyzes with lightning.
I just noticed, Luck also resists magic that induces status effects and makes opponents lose control over their body. Well, that made him even stronger. Sayaka's sleephax might not work, even if she manages SOMEHOW to him him, but his senses, skill and speed are too sharp.
Eh, it's even worse for her. It's not the first time Luck has seen swordsmen in action. And his armor protects his body so he can block the strikes.
He was on top of his stamina in near death state and still wanted Vetto (the 1.45 megaton guy) to perform his strongest attack again, and being on adventures for weeks with many fights is nothing new to him. He has never shown to be exhausted.
