I would rather up this card a bit, "once per turn" is too weak but cool :)

Oh? How would you up it?

If you still read this, and if you want to dive into the "YuGiOh strategy" (by the way i'm not an expert, i don't play the game irl but i really like strategy and i studied card games), well you should read this.
But remember it is your card so if you don't want to bother with balancing and borring Ridiculously complexs stuff, just don't mind my comment :p

Nowadays there is plenty ways to "break" a trap card :
-Destroying
-Sending to the graveyard
-Banishing (either face up or face down)
-Removing from the field
-Returning to hand
-Negating
-Stealing (taking control)
-Fliping back to face down

Yes this is not a joke, none of these things are strictly equal. YuGiOh player get really mad when you don't use the right vocabulary, because a card that "return to hand" do "leave the field" but isn't "sent to the graveyard", as well as "banishing" who doesn't destroy at all. Well, some effects I listed aren't very common. The most common ones are banishing, negating and destroying.

So, if you want to keep your initial idea but make it more viable, you should rather say "... none of your face-up Trap cards can leave the field or be negated"

i don't want to go even deeper with card advantage or the infernal "targeting system" so i'm stoping here ^^

Have fun :3

Well, to be honest, these cards were made with the old ways of playing (up to the first quarter of 5D's) so I made them to fit how I used to play back when I was a kid. None of it is meant to be strictly competitive as cards I make come to me in dreams that play out similarly to the Anime.

I did look into the wordings on cards nowadays but I only for a short bit as this is all in the ways of fun.

The way I worded it is if a card targets a Trp Card to destroy it and the card would be sent to the Graveyard then it'll be protected... Like I said, all in the name of fun.

i think there's already a protection card like this

Eh, if so, one more won't hurt