All in all, I expect [casthaven]Malfunction[/casthaven] to be a comparably bad-but-powerful removal spell much like Sleep Paralysis was
Madness (If you discard this card, discard it into exile
If you do, put this card into your hand as it resolves.) Flash Flying When you cast this spell, draw a card
As a side effect, these also typically extend the length of Commander/EDH games by 20 minutes
Kaladesh, like most artifact sets before it, was pushed to the limit as far as power level was concerned, which led to multiple bannings in Standard (and was around the start of bannings being so in vogue in Standard)
You can tap any untapped creature you control to convoke a spell, even one you haven't controlled continuously since the beginning of your most recent turn