Does the marriage contract become void due to the wife practicing sorcery or concealing her illness, and what are the implications of that if the husband has already consummated the marriage with her?

Sorcery is forbidden and is of two types: sorcery that involves disbelief (kufr), which relies on drawing close to devils and is considered disbelief and apostasy; and sorcery that does not involve disbelief, which relies on drugs and similar substances, and is considered merely forbidden. Accordingly, if the the wife's sorcery involves disbelief (kufr), then her marriage is invalid due to the dissolution of the contract by her apostasy. However, if her sorcery does not involve disbelief, then the marriage is valid, and this is considered an act of transgression (fusuq) on her part.

As for the wife's illness: if it existed at the time of the contract and affects the marital objectives (such as intercourse or pregnancy), then the husband has the option to annul the marriage. If it does not affect marital life, then the husband does not have the option to annul it, and it is recommended to inform him about it.

In summary: If the woman's sorcery constitutes disbelief (kufr), then her marriage is invalid. If her illness affects marital relations, then the husband has the option of annulment. Otherwise, the marriage is valid, and the husband should strive to reform his wife or separate from her if she does not respond, in order to protect himself and his children from the harm of sorcery.