What happens?

[Fenster]

{sakashimas student} into {hero of bladehold}
Battlecry? Tokens?

[Tetsomori]

R u attacking? As in did you "ninja" her into play?

[D3g3n]

Since Ninjitsu only can be played once an attacker is declared (specifically after declaration of blockers), a Sakishima Student copying any creature with Battle Cry would not cause Battle Cry to trigger. Battle Cry only triggers when attackers are declared.

Also since Bladehold's token ability is triggered at the same time as when it is declared as an attacker, your copy will not spew out tokens.

Basically,
"When X attacks" is short for "when x is declared as an attacker".

"Attacking" refers to the state after a creature has already been declared to attack.

[Fenster]

K thx