Will be fully obsolete once Solemn Notice comes out, but for now it's an option that some people may consider.  It's definitely good in shutting down a pendulum summon, whereas Black Horn of Heaven cannot.  But most of the time the opponent will be summoning one monster at a time.  Majespecters Normal Summon a lot and Kozmos can Special Summon outside of the Main Phase, so this card won't affect them too much.  The opponent gaining a card often makes this card a +0 at best and a -1 at worst, making it a risky card like Dark Bribe.  But Dark Bribe, in its time, was worth the risk because it enforced lockdowns and helped aggro plays.  This card, not so much. HERO decks can side deck this card because the draw effect triggers Dark Law's effect.  Overall, not good but not bad either.
 
2/5

Thanksgiving week is upon us!  Are you as hungry as I am?  But we open a new week, a short one in lieu of the Holiday, although you get another twofer on Wednesday!  We open the week with a Counter Trap, in Grand Horn of Heaven.  Let's compare this to the old original card, Horn of Heaven.  The latter lets you negate the Special Summon of a Monster by Tributing one of your own Monsters.  If you're successful, that's a -1 one for you.  Your opponent loses their Monster, but you're out Horn of  Heaven and the Monster you Tributed.  Grand Horn of Heaven also lets you negate the Special Summon of a Monster, (note this can only be done during the Main Phase however, specifically your opponent's) but as opposed to Tributing a Monster, your opponent Draws a card after.  In terms of total advantage, your opponent only breaks even.  They Draw (+1, but lose the Monster they were trying to Special Summon, -1, for an even) while you sit still like with Horn, at -1, for using this card.  While the opponent only breaks even, it's a net +1 for them as they gain an extra card compared to the one used by you.  Nevertheless, it's cost free, and a solid enough card.

Rating:  3.25/5 
Art:  4/5

This Thanksgiving week starts with Grand Horn of Heaven. If you're not familiar with the Horn trap cards, they are Counter trap cards that involve negating the summoning of your opponent's monsters in one fashion or another. Grand Horn of Heaven is the one that can stop multiple summons at once. The big thing now is the Pendulum summoning, and this card can shut that down. But it must be during the main phase. Any other summoning at any other time outside of the Main Phase does not work. It also ends their Main Phase. That is good as it places them in a very awkward situation, and if you activate this during your opponent's 2nd Main Phase, it ends their turn. The minor drawback is when Grand Horn of Heaven does negate the summoning, your opponent draws 1 card. Depending on the situation, Grand Horn of Heaven can cause your opponent a huge headache and wasted resources, leaving them at a huge disadvantage. Im sure smart players can and will find a use for this card.
 
3/5

The grand daddy of horns and Spell Speeds, Grand Horn of Heaven says "no" the way Solemn Judgement used to do. Counter Traps have always had a fond place in my heart for being the end of all chains in terms of power. Grand Horn of Heaven is no different. Whenever your opponent tries to Special Summon a monster, you can negate and destroy however many were trying to be Special Summoned. However, it can only be activated during an opponent's Main Phase.There is no cost on this card, but there are some positive aspects for your opponent, they get to draw 1 card. Overall, this card benefits you because it ends the Main Phase instantly. This is an excellent Side Deck card against Pendulum Summon decks. 
 
Score: 3.5/5 MST bait with no Graveyard effect. Still good.
Art: 4/5 "That is the horn of a carpenter." "You must choose. Choose Wisely."
 
-WarlockBlitz

What a beautiful piece of artwork this card has; truly this is meant to showcase how much of an upgrade it is to the original Horn of Heaven. If I recall correctly, the original Horn forced you to Tribute a monster in order for the Trap to destroy an opposing monster. This version acts a bit more like Solemn Judgement, albeit a nerfed version. It negates an opponent's Special Summon and destroys it, that alone makes it good. But wait, there's more! You let your opponent draw 1 card, then you end his Main Phase then and there. So yes, you're giving your opponent something in return; however, if this effect goes off during his Main Phase 1, you've essentially stopped him from attacking or laying down any more Traps. It's quite the stall, especially if you manage to pull it off early on! 

Some may look at this card and say, “Meh, good but not good enough.” And maybe they're right, maybe it's not as great as Solemn Warning or Bottomless Trap Hole or even Pulling the Rug. But hey, if you've got this card, why not give it a spin? It gives you field advantage for just one turn, but in this game, one turn can make a big difference. 

Final Score: 3.5 / 5

How is everyone doing? This week its Thanksgiving. :) Anyways lets get on with this review.
 
Grand Horn Of Heaven.
 
This card has a lot of potential. The fact it can stop mass pendulum summons is great. Then it ends the main phase. So if you use this during there first main phase it will send them right to the battle phase. Most decks in today's game wouldn't have anything to battle with. The only "down" side is they get a draw.
 
Now stopping one of there major plays to push for game the extra card might not even help. Plus just combined it with Dark Law and you get a free card from there hand. I think its great.
 
Rate 4.5/5