So I attacked a monster that was face down. The monster then flips up and my opponent activates Spikeshield with Chain, and then chains it to another one so the monster had like 6000 def or something. I had enemy controller to chain to that to turn him to attack and the game wouldn't let me. Is my chain knowledge a bit off or is the game a bit faulty?
You were in the Damage Step.
E-Con can only be activated in the Battle Step (or anything before).