As an artifact that does nothing else this could be a lot cheaper. I don't even think the ability should stand alone.

Maybe something based on Tajuru Preserver?

> "Spells and abilities your opponents control can’t cause you to discard cards or sacrifice permanents."

I notice you have a lot of these dedicated cards that entirely shut down one ability the other deck might have. Some of them might make for interesting counterplay (especially if they are creatures or otherwise do something else proactive in addition), but I would pick fewer of them than you have because you don't want the deck playing them to draw those cards to often when they don't matter or the deck playing against them to be too constantly unable to use their own effects at all.