Is your Spell card returned to your hand or destroyed and sent to the Graveyard when Spell Reclamation is attached to one of your Spell cards and your opponent plays Malevolent Catastrophe?

Answer 1

Spell Reclamation does not 'attach' to anything. You activate a spell card, and chain Spell Reclamation to it. So;

If Malevolent Catastrophe is chain link 1, the spell is chain link 2, and Spell Reclamation is chain link 3, then Spell Reclamation will resolve first, your spell will resolve second, then Malevolent Catastrophe will resolve last. Instead of going to the graveyard, your spell will return to hand instead.

If your spell is chain link 1, Spell Reclamation is chain link 2, and Malevolent Catastrophe is chain link 3 (it's valid at any link in the chain as long as it's in response to an attack declaration) then Malevolent Catastrophe will resolve and destroy all S/T cards. Spell Reclamation will resolve without effect, as the card it was trying to affect is already in the graveyard. Lastly chain link 1 will resolve correctly as normal.