**Note this is NOT the same as Zanpakuto level. A Zanpakuto's level is in it's closed state, and represents the strength of the weilder and Zanpakuto's link, the Shi-kai represents the amount of trust and workmanship between the Zanpakuto and Shinigami.
Level 1 Shi-kai: A very very weak Shi-kai, it's attack power is almost not even there.
Level 2 Shi-kai: Still a very weak attack, usually more of a defensive then offensive.
Level 3: Slightly stronger defensive but still does not yeild well to offensive.
Level 4: Powerful enough to make a person take there knee.
Level 5: the midway point. Strong enough to leave an impression on a person.
Level 6: Stronger then the begining it's power is enough to defend and yeild well to offensive attacks.
Level 7: Strong defensive and offensive capabilities.
Level 8: Has enough stomping power to make a person sweat.
Level 9: A strong Zanpakuto usually in 4 or 5 seat but there are some exceptions.
Level 10: The strongest of the shi-kai allows for offensive and defensive, as well as the level of Shi-kai release needed to eventually gain ban-kai. [u]