Unexpected and really bad.
Beating can be a word for severe setback. Blow is another word for severe setback.
cramps
severe
The suffix that means sudden severe bleeding is "-rrhage." An example of a term with this suffix is "hemorrhage," which refers to sudden and severe bleeding.
Apyphony.
Gust is another word for a sudden strong blast of wind.
small ;not major or severe
Another word for sovereign is severe and is used in a pacifistic way. Aplus answer independent.
Panic, sudden, alert, are words for emergency.
U can call it depend on country. For example, Sudden Attack North America is SANA and Korean Sudden Attack is KSA
severe, extravagant, strong, extreme
Another word for very strict or harsh is stern.