If your piloting a control based beat down deck, be it Elemental HEROs or Dino Rabbit, you want your monsters to be able to walk over anything your opponent has on the board, and keep your spells and traps for something bigger, like the boss monsters. If your level 4's couldn't win in a battle against your opponent's 0-drops, you know your in deep shit. Lets just stick with HEROs and Rabbit for the moment, and not think of any other control beat decks. Chances are, the only time you would feel an insufficient in power, and also the need of more power, would be in a match against another HERO or Rabbit.
Why is power, or in YGO, the ATK stats important in these match ups? Normally, HEROs have their 1900 line, and in a mirror match, players would trade monsters if they do not want to waste traps on a lesser HERO, waiting for cards like ZERO or Shining. In Rabbit, how many times did you wish you could just walk pass Kabazaus with your Guaibba and not wasting your Forbidden Lance in hand? Some might argue that the traps is what matters in these match ups, I'm not saying thats wrong, but thats not all there is to these grind games. When a HERO player drops Photon Trasher on to the field, the game would suddenly favor the card's owner. Photon Trasher isn't a game ending card in any means, but it has 200 more attack points than HERO's 1900 line. This forces your opponent into playing traps, spells, summoning XYZs or dropping Honest to get over it, effectively putting pressure on the board, especially since it wasn't normal summoned.
A big contributing factor why the 2100 attack line in so good against these decks would be the ineffectiveness of traps against them. Don't get me wrong, a single BTH or Prison is enough to get rid of the Trasher. But in a HERO mirror, especially early in the game, you wouldn't want to set more than 1 face down, unless you have a Warning or such. Gemini Spark contributes to this, because setting more than 1 would let your opponent plus off you like no ends. Looking at a HERO (and also Rabbit's) trap line up, the Solemn Brigade took 3 slots off the 10 or so copies of traps. And you don't really wanna use Solemns on a 0-drop, especially if the game is early. In grinding games, every life counts, a direct swing from Trasher may prove sufficient in the long run.
Thats all I have to say about how utterly amazing Trasher is in mirror matches, but why is it good? Because it is a card that could walk pass any level 4s your opponent might throw at you. Basically, it slightly weaken's your opponent's power line and affects how the game should be played altogether. In conclusion, I do feel that cards that alter power lines would be very important in these match ups. Which leads me to the card I wanna discuss today. Similar to what Kyde said on his blog, Seal of Oricharos increases your power line by 500. That's enough to steal games in a control mirror grind game. But I do feel the card's drawback is too much for decks like HERO and Rabbit. We still need our extra to fully utilize our advantage, unlike decks like Rock Stun (which Seal truly shines in).
Burden of the Mighty is a very simple card, it decreases your opponent's power line in accordance to their level, here, we are mostly talking about 400 points. It does not affect XYZs, so your opponent can always overlay their monsters to make your card dead. So, why is it good? Simple, it wastes your opponent's resources. Imagine, your opponent has a field of Trasher and Allius, pretty amazing field for a grind game, but you place Burden on the S/T zone and summons Thunder King. Thats not all, it forces your opponent to get rid of it early. Burden also makes HERO fusions in the ranges even an Allius could take out.
How does this benefits Rabbit? It makes Guaibba an instant trap magnet, baiting you everything so you could drop Rabbit or Tourguide safely. Thats not all, your 1900 line becomes 2300, while your 1700 becomes 2100. That is basically gonna change the tempo of the game until the inevitable MST shows up. If your opponent HAS to prison your level 4s, you know your in a better position than he is. If you have Allius and Burden, you could just attack your opponent's Allius, knowing your gonna deal damage, cause his gonna take out Burden first. You setting a face down after that is gonna be huge, cause that card might be Spark, it doesn't have to be, but your opponent is gonna do everything they can to try to play around it, which affects their tempo instantly.
This card is more powerful against HERO than it is to Rabbit. While there is some use of this in a Rabbit mirror match, Laggia and Dollka are still too powerful. Whereas in HEROs, the XYZs are usually unprotected from traps and spells. In short, Burden forces your opponent to go into their extra deck for answers. Also, you can even try siding a copy of this against Agents and Chaos Dragon's. It doesn't have to stay on the field for long, since you just need to get in there and take out a big boss monster, like how Leeching the Light does, except this card stays on the field until something happens to it, you still fall short to Krystia by 100 thou.
To wrap things up, I would really recommend this card to any who is trying to catch your opponent off guard in a HERO mirror. Its not the most effective of cards, but it does it job in slowly changing the games tempo and gaining you slight advantage, a little at a time. I wouldn't play this in anything but a control deck, and wouldn't play this against anything thats not a control deck. This is the kind of card that would only shine in a mirror match, where the power line of both decks are equal. Hope this helps.