Sale deed voided and nullified

A very complicated issue that has to be guided by a local advocate, to study the relationship between A & B, why there was expartee decree, the judgment stated reasons and whether summons was duly issued to the defendant, etc.,

Dont buy any such property, you will be in trouble for nothing

It is better to consult  a local prudent lawyer for appreciation of facts / documents and professional guidance 

The facts posted suggests no encumbrances in purchasing the property unless there was fraud inherent in declaring B ex-parte. Even in such an eventuality, the buyer is entailed for due protection of law as an innocent third party. In other words, even in such a case, B's remedy would be restricted against A, the prospective purchase would no way be liable.