One of the things we've been used to since magic was born is the fact that discard spells, with some extremely rare exceptions, are sorceries.

This is because WotC believe that discarding thing in the draw phase is a feelbad moment. The problem with this view is that topdecking a discard spell is a way worse feelsbad moment to me, because it's actually worse than just topdecking a land. It's essentially skipping your draw step.

But this is only true only if all discard have to be sorcery. Were some discard printed at instant speed, topdecking discard spells wouldn't feel as bad as essentially skipping your draw step for no reason, and would be a more playable mechanic just because of that. It would still be a worse topdeck that a counterspell for example because of the chance of you whiffing on a land draw of your opponent, but it'd be way less shitty as a disruption mechanic than it currently is, which is essentially play it early or it's mostly useless.

Of course, straight current-level discard at instant speed would probably be too good, but something like a duress that cost 2 life too could be printed at instant. If counterspell at UU can deny a card AND gain you tempo, i don't see why an instant Distress is unacceptable. Sure, counterspells are proactive while discard is reactive, meaning you want to keep the mana open, but in my opinion this should balanced by the fact that counterspells gain you tempo where discard doesn't.

Ah, and obviously instant speed playable discard already exist but it's blue zzzz

I thought about this mostly because i realized that an instant speed Unmask would actually make black a good color against stupid combo decks trying to go off T0 that you sometimes encounter without forcing you to go blue or accept those random losses, while still being distinctly different and worse than FoW as a card.