- THREATENING ROAR
[Trap Card]
Your opponent cannot declare an attack during this turn.
If you have a Brain-Jacker face-down on the field you can prevent your opponent from attacking it, and thus will get its effect next turn. Although Waboku would also allow you to get brain-jakers effect your opponent would have the entire main-phase 2 to deal with the monster you took control of. Negate Attack achieves the same effect as Threatening Roar.
Same goes for Cyber Jar, Fiber jar etc. Can protect Tribute Fodder. Your opponent won't be able to suicide a weak monster into Reflect bounder.
Pro: Protection for One whole Turn.
Pro: Protects effects as well (Flip effect or Reflect Bounder)
Pro: It can be chained to any card that would destroy it. Therfore you can activate it jsut like a waboku.
Con: Unlike Negate Attack it can be chained to by spell-speed 2 cards, such as Royal Decree or a Call of the Haunted targetting Jinzo.
However that's not a major problem:
Max: 3x Royal Decree + 1 Jinzo is four chances to stop threatening roar
Whereas your opponent usually Packs at least 5 methods of destroying Spells and Traps, so there's a greater chance of destroying NEgate Attack before it could get its effect.
Con: Sometimes you'll want your opponent to attack and just protect the damage (e.g when you have a wall of Illusion) Waboku will allow that, threatening roar won't. And sometimes you'll want to activate a waboku in your own turn.
Conclusion:
R.I.P Negate Attack
If its difficult to find wabokus in your area, stop trying: Threatening roar will often be better.
One more thing: IT IS A COMMON