I agree. There should be a clear indicator that the attack and ninjutsu go up on the unit that causes the chase. Also, I myself am confused if it actually works correctly because I haven't noticed anything either after testing the Ninja Assist on the Kakashi clone multiple times.

Hello,
I have asked about this for you and will get back to you once I hear back about it.
Thank you for bearing with us on this and sorry for the inconvenience!

Alright, sorry for the delay on this issue, we did some testing with this card and it does seem to work, the arrows simply don't display when the chase activates. Testing was done in the infinite illusion mode with a non scaling ninja and significant growth was shown for the ninja. I will but in a bug ticket for these cards to notify the techs about this issue in case this is not intended.
Sorry for the inconvenience here and thanks for bearing with us on this issue!

Hi. Thank you very much for addressing this issue.

If the buff is working can I request the ninjutsu/attack up arrows be displayed on the units every time the chase is activated? It will be of great help to us.

Hello, yes, that it what I meant when I said I was putting in a bug ticket about the arrows not display. I've already submitted the ticket for this.