Light, easily.
- Move with the speed of light
- Punch and kick with the speed of light while being able to infuse your fists and legs with Haki
- Use light swords
- Flight
- Lethal and destructive lasers
Who knows what awakening holds.
Yami's main ability is shutting off other peoples DF powers, while also having the draw back of receiving more damage and pain from attacks.
BB already told us not even light can escape his df.
"Not even light" means everything else can't either. Which has its limits in practice. The Yami user can attract the Pika user, but the Pika user can still launch destructive beams mid way as Ace launched his fire spears. Also, a Haki barrier can keep you away from physical contact with the Yami user and also interfere with his DF.
Imagine the Yami user attracting the Pika user while the Pika user launches into the Yami user with a light speed fist he infused with barrier and conqueror's Haki, while the Yami user's body has the damage and pain received amplified further.