When there are many enemies that are grouped together, use Shizuka and equip 
Fleck. Then, run
toward the enemies. Press Triangle while running. Try to hit an enemy with 
more health than the
others. This attack deals damage but also plants a bomb on the enemy. Hit 
the enemy with any
other attack to detonate the bomb. The explosion of the bomb does not hurt 
you.
When fighting a Juggernaut, use Benkei. Equip Benkei's club and hold 
Triangle until his club glows
and sparks. Then, release Triangle and charge into the Juggernaut. Be 
careful not to press R1
before holding Triangle.
While in Kamui mode, press Circle if the "Circle" symbol appears instead of 
any other attack. This
deals more damage. If the "Circle" symbol does not appear, then choose 
another button (for example,
Triangle) and press Circle afterwards. This deals more damage.