Another spellskite question...no point making a new thread since it all deals with spellskite.
If I give spellskite shroud, can I effectively counter every spell (decay, plow, bounce, bolt, etc) that targets any artifact or creature on my battlefield for the rest of the game???
If so, would hexproof also do it, even though I am targeting it since it was my opponents spell originally?
That would be the bees knees in mud/fish.
No, changing a target means the old thing ceases to be a target and the new thing becomes a target...you can target any spell or ability with Spellskite's ability...but if skite has shroud/hexproof changing the target of the spell or ability to spellskite is an illegal action since it cannot become a target. So Spellskite's ability will do as much as possible when it resolves which is nothing.