just be patient, and reach level 53.
you can catch ninja dog shiba at lvl 53, shiba will make your main chase low float and cause repulse.

while you waiting, learn the game for you to be better. like how to make good combo, how to make defensive/offensive line up. try to mix and match your ninja in arena.

if you are stuck at one point about something, open this forum and type the keyword of your problem in search bar. maybe someone have the answer. if you dont find it in search bar, make a thread about your problem.

once again, just be patient, and keep leveling and reach level 53.

hope this help,
good luck and have fun