Hi,

villian can have a wide range of hands here. I think his most likely holding is A decent kicker or a semi bluff (spades/56s/67s).

I do not think that he will bet his hand on the river nor call a big bet after you called his reraise.

If villian holds a set or two pair he might call a big reraise so I think your reraise is ok. It is important to get the money in before another spade hits the river and puts you in a difficult spot or kills the action. A pairing board might get you into trouble, a 5 might kill the action or make him a better hand. So protecting your hand seems like the right move to me.

Chris