• systers,
• shaters,
• sissters,
• shuters,
• shitters,
• systes,
• hesters,
• sheters,
• shispers,
• shister,
• ssters,
• shoters,
• sheisters,
• chesters,
• shisters,
• susters,
• shyster,
• shastere,
• hysterps,
• Hysters

• shoestring,
• shuster,
• shyster.

The adjective form of "shysters" is "shysterish". However, it is worth noting that this term is not commonly used or recognized, and it is more common to describe someone as being "shyster-like" or "shyster-esque" instead.