Just about any effect that says "draw 2 cards" has potential to see competitive success. However, many cards that follow the formula of "give up one other card to draw two" have failed to see widespread success due to narrow activation requirements. Many of them only work in decks that have specific inconsistencies. Destiny Draw's amazing when you're loading your graveyard with Destiny HERO – Malicious, but having either Destiny Draw or Malicious in your hand without the other is asking for a bad time.
The best of these cards have historically been the ones that allow more flexibility in how they're used. Sacred Sword of Seven Stars is Limited to one per deck since it uses monsters from the hand and field, and thus has inherent synergies with Dragon Rulers. Destiny Draw used to be Limited due to interactions with the powerful graveyard effects of Destiny HERO's at the time, as well as the ability to search out relevant fodder through Elemental Hero Stratos and Reinforcement of the Army.
Allure of Darkness has one of the largest pools of compatible cards, including literally every Dark monster in the game, and as a result has been Limited for a very long time. Soul Transition follows in these spell's footsteps as a strong and flexible draw card that shouldn't be overlooked.A Unique Soul
While it's preferable to draw cards on your own turn, being a trap card gives Soul Transition some interesting little advantages. Let's look at the most basic. If your opponent uses an effect to try and clear your monster, you can chain Soul Transition to Tribute it and draw two cards. This essentially blanks your opponent's effect and can turn your even exchange into a quick plus of card economy. Similarly, if you've had Soul Transition down for a turn, Tributing off a monster in response to an effect negation card can mitigate the cost by ensuring your monster's effect resolves properly. While applications like this are possible in nearly every deck that could afford to run Soul Transition, there are definitely some decks that can use it to even stronger results.Putting Your Soul Into It
First of all, if you have Level 4 monsters that can generate free cards the instant they're Normal Summoned, Soul Transition will probably fit into your deck. Monsters that search upon their Normal Summon like Traptrix Myrmeleo, Volcanic Rocket, Satellarknight Deneb, and the Gadgets all give you an extra card immediately, but if they're run over in battle, the quick boost in card economy is suddenly lost. Soul Transition helps to lock in your advantage by turning the monster into even more cards. While you may have not gained actual card economy through playing Soul Transition, it helped ensure your position since it prevented your opponent from gaining a +1 of their own through battle. On top of that, if your opponent was going to use a card effect to clear the monster instead, chaining Soul Transition will further boost your position by nullifying that effect entirely.
Despite quick and efficient Normal Summons being almost everywhere, not all such decks use Soul Transition equally well. A controlling deck that doesn't Special Summon tons of monsters will get more value out of Soul Transition than one that builds up into huge combos. For example, a Traptrix deck will often only Special Summon monsters when going for problem-solving Xyz plays, keeping Soul Transition live. Compare that to a deck like Satellarknights, which Special Summons on nearly every turn after the first, and Soul Transition will often never be activated. While the card's still potentially useful in decks like Satellarknights, it runs the risk of being a dead draw after the first turn of the game, unless you change your plays specifically to adapt.
The other category of cards that love Soul Transition are monsters with effects that trigger when they go to the graveyard. Monsters like Elemental HERO Shadow Mist and Goblin Zombie pair perfectly with Soul Transition, netting you more search effects when they're Tributed. Many decks with graveyard effects like those need a little setup before they can start to combo off, making Soul Transition an incredibly strong way to gather combo pieces while enabling effects. Soul Transition also lets those monsters dodge effects that would banish them or otherwise prevent them from hitting the graveyard. While some optional "When… you can" graveyard effects won't activate, as the last action before they could activate is drawing cards, the effects that do trigger can be incredibly powerful in tandem with Soul Transition.Spaceships Have Souls, Too
Let's do a quick overview of what Qliphorts do. Every Qliphort monster, barring Normal Monsters and their big bosses, can be Normal Summoned without Tribute by making their Level 4 and ATK 1800. The deck revolves around establishing overwhelming numbers of cards through the vital search effect of Qliphort Scout, and seeing Scout is often the difference between winning and losing the game. While the deck is an OTK strategy, it rarely Special Summons outside of powerful Pendulum Summons and the finisher card, Qliphort Disk, both of which usually only happen once the deck has established a dominating position. The Equip Spell Saqlifice is key, protecting the equipped monster from being destroyed by battle, and then searching out whatever combo piece is missing when the monster finally does fall. Oh, and lastly, two of the deck's key monsters have effects that trigger when the monster's Tributed.
Yeah, Soul Transition seems like a perfect fit. Since everything becomes Level 4, any early-game Normal Summon is fair game to tribute. The draw power is much welcomed to help see key cards like Qliphort Scout as soon as possible. The deck doesn't Special Summon before getting to those cards, so Soul Transition's drawback will almost never kick in. Saqlifice both encourages your opponent to use a card effect to clear your monster and searches a combo piece when the monster's Tributed, pairing with Soul Transition on two different angles! Then there are the stars of the Soul Transition show, Qliphort Helix and Qliphort Carrier. Both of these monsters have effects that trigger upon being Tributed, regardless of the means. These effects can pair with Soul Transition to make for powerful disrupting plays and help seal the game for an OTK the following turn.
When Qliphort Helix is Tributed, it destroys any spell or trap on the field. When suited up with Saqlifice, Helix will often survive until your opponent's End Phase, allowing you to Tribute it with Soul Transition and earn an astounding number of effects. First you draw two cards. Then you get to search for a Qliphort monster, usually Scout. Lastly you get to destroy one of the freshly set traps your opponent may have played in an attempt to stop your push the next turn.
What it results in is a quick 3-for-4 swap in card economy, giving up Soul Transition, Saqlifice, and Helix for two draws, a Qliphort Scout, and an opposing backrow card. However, you can immediately leverage that +1 into a +3 or more through the effect of Qliphort Scout and the Pendulum Summon of the sacrificed Helix from the Extra Deck, and often that shift in card economy is enough to beat your opponent outright with Qliphort Disk and the accompanying Pendulum Summon.
Qliphort Carrier isn't nearly as strong offensively as Helix when paired with Soul Transition, but its effect is an all star for turning Soul Transition into more copies of the Limited trap card Compulsory Evacuation Device. When Carrier's Tributed, you get to target any monster on the field and return it to the hand. While this is powerful when Tributing it for a Tribute Summon for its ability to clear defenders out of the way, triggering it on your opponent's turn is even better. With Carrier on board and Soul Transition set, any Extra Deck threat your opponent could field can be immediately sent back to the Extra Deck in an instant, all while netting two draws and a monster to Pendulum Summon back later.
You can also use that combo to break up Xyz Summons before they happen, avoiding problem effects like Evilswarm Exciton Knight, or leaving a Burning Abyss player stranded on a Tour Guide with virtually no way to field more monsters. Disruptive plays like this can keep many decks off-balance just long enough to sneak in a win through a powerful swarming play, and just like with Helix, the draws and potential Saqlifice search help establish the insanely powerful boards that Qliphorts thrive off of.Embrace The Soul
At the same time, Soul Transition's restrictions play perfectly with the nature of one of the most fearsome strategies in competition today, playing off of Qliphorts' unique properties to leverage a simple "draw 2 cards" effect into a flexible disruptive trap. Whether you're playing this powerful deck, or are trying to find a way to boost your rogue control build, Soul Transition's most definitely a card to consider. I'm looking forward to seeing it played in all kinds of places.