I'll do it.
Effect Veiler
Effect Veiler is a monster that can be used in the hand and send himself to the Graveyard as a cost to activate his effect, which is to negate an opponent's monster effect. It can hurt most decks from carrying out a great strategy, like Inzektors. Should the opponent summon Dragonfly, you can stop the swarming from happening by simply sending Effect Veiler to the Graveyard. At least for that turn, your opponent can't grab that blasted Hornet from his Graveyard.
Effect Veiler can also be used WITH Inzektors if one finds the room for it. Being a LIGHT monster while Inzektors are DARK, Inzektors would have a monster that protected them from other monster effects and be given the potential to summon Black Luster Soldier - Envoy of the Beginning or Chaos Sorcerer. Also, being a Tuner monster, it can be used to Synchro Summon a Level 5 monster (as lots of monsters tend to be Level 4).
The drawback of Effect Veiler is that it can be a waste of space if dueling the wrong Deck. It can't negate Sangan and other searchers since their effects go off in the Graveyard. Also, since it needs to be sent to the Graveyard as a cost, his effect won't work if Macro Cosmos or similar cards are on the field. Finally, being a weak monster, its major enemies are the Virus cards and King Tiger Wanghu.
To summarize, Effect Veiler is a great card, but it's best left in the Side Deck; you never know when you might actually need it.
Maxx "C"
Maxx "C" allows you to draw a card for each time your opponent Special Summons a monster. How does it affect the Meta? Simple; pretty much anything new involves Special Summoning in some way, and some effects can even be chained to, which brings out the usefulness of this card. Being at Speed Spell 2, this card can be chained (from the hand) to any effect like Monster Reborn.
Let's look at Wind-Ups. They have that dreaded loop that eats away at your hand, and usually your opponent won't stop until your hand is gone. Maxx "C" can be used to counter this, but most of the time it'll need to be part of the first hand. But if Maxx "C" is in your hand by the time the loop begins, foiling your opponent's plans will be so much fun.
Maxx "C" helps in keeping hand advantage even after Wind-Up Hunter blasts away so many of your cards, as many more Special Summons are involved before it's summoned again. Maxx "C" works well with Tragoedia, as the chances of your opponent proceeding with the loop even after you activate Maxx "C" are not low. As we all know, Tragoedia's ATK and DEF depend on the cards in your hand, and it's easy to summon since in most duels players suffer from Battle Damage anyway.
Maxx "C" can be used against any Deck that Special Summons vigorously (including the not-so-horrible-now Infernities), and being an EARTH attribute allows you to Banish it from your graveyard to Summon Gigantes, which has a Heavy Storm effect when destroyed by battle. However, just like Effect Veiler, Maxx "C" needs to reach the Graveyard for its effect to activate, otherwise it won't work. Also, many Decks don't rely on Special Summoning as the Meta (like Monarchs), leaving Maxx "C" as a dead draw.
To summarize, Maxx "C" belongs in the Side Deck, unless you have other uses for it. If nothing else, it can be used to play mind games with the opponent, preventing him from making a big play. However, that doesn't always work.
Battle Fader
A card that can stop a direct attack and end that turn's Battle Phase. It works to give you an extra turn to plan your strategy, and also stops those annoying OTKs. Look at both Wind-Ups and Inzektors. Their strategy is to get rid of your field/hand before attacking. You'll have better luck against Inzektors with Battle Fader, but can halt the plans of both if it's in your hand when an attack is declared. Although not part of the current Meta, Morphtronics buffed by Limiter Removal won't be able to carry out their OTK if Battle Fader is dropped on the field.
This card's usefulness after being summoned is up to the player. It can be Tributed for a 1-Tribute Summon, it can be used as a Synchro or even Xyz Material. In any case it can help bring out a powerful monster that can turn the match in your favor. Most people use it to summon Caius the Shadow Monarch (a good move, I might add), but other possibilities include Synchro Summoning by tuning Battle Fader and a Level 4 Tuner, or summon Kinka-Byo and another monster by its effect and Overlay them all for Baby Tiragon or Galaxy Queen.
The drawback is that Battle Fader is Banished once it leaves the field, and like Effect Veiler and Maxx "C", Debunk and Divine Wrath are the worst threats Battle Fader can face. Cards that prevent Special Summoning like Archlord Krystia can stop Battle Fader from being summoned.
Surprisingly, Battle Fader may not always need to go to the Side Deck. If a player plays a Deck that often leaves him open (like Spirits), Battle Fader may help prevent any Battle Damage. It's a good card to carry, but it also depends on the strategy a player has.