My attempt at something that kindasorta wants the best of two worlds. Essentially a push protector to replace the likes of Heavy Storm and Cold Wave.
SPELL | Normal
Target 2 Set Spell or Trap cards your opponent controls; those targets cannot be activated until this turn's End Phase. This card's activation and effect cannot be negated, and cards and effects cannot be activated in response to this card's effect. You cannot activate any other Spell cards during the turn you activate this card.
First of all, this card requires your opponent to have at least 2 Spell or Trap cards face-down on the field, which won't always happen, and thus this card should lean more towards the Side deck. Then it does half of Cold Wave's job - it keeps those cards from being activated until the end of your turn. Additionally your opponent can't activate them in response to this card's effect, which means that you likely won't "waste" this effect. The benefit this card has over Trap Stun is that it also locks down Quick-Plays such as Book of Moon, the Forbidden series etc.
One of the most obvious but practically least important drawbacks compared to the aforementioned cards is that if your opponent has a full backrow, you can't disable it. Also, obviously, unlike Heavy Storm it doesn't remove those targets from the field, so if your opponent survives your push (which is actually more likely than ever, given the high count of hand Traps), they can still get mileage out of their cards next turn since, unlike Cold Wave, this card doesn't restrict your opponent from playing new cards. It does, however, stop you from activating any other Spells during that turn. While this is not very important against decks that rely a lot on monster effects to win them the game, it should at least help mitigate its impact when used with, for example, the field-clearing Dark Hole.
I also created this card with the thought of the "blind MSTing" situation. On an average scenario, you'd likely set your MSTs in hopes of being able to snipe your opponent's backrow before it can be used, and otherwise you'd almost certainly try and use them on the first set card you see, when you're in a situation when you can potentially push for game, with only few situations warranting keeping MST for use against specific targets (Continuous S/Ts, certain equips etc). This results in a bipolar situation - you are either punished for MSTing into something chainable, or rewarded for using it blindly. Your opponent is also "rewarded", for lack of a better word, for running chainable things - in a sense, it becomes a situation of who was able to set first, which is not ideal. This card should prompt players to think more carefully about activating their cards, hopefully alleviating situations where players feel intimidated by a blindly-set 4-card-backrow.
tl;dr this is my attempt at a "smart" card and it probably failed badly. Opinions?