Sylvans are a fun little deck that you don't see too much of on MD (or at all, still haven't run into a single Sylvan deck), hopefully a decklist fit for Master Duel can encourage someone to play it. Firstly, before we start, you should know what kind of deck Sylvans are and what to expect.
Sylvans aim to excavate (also mill) their monsters, all of their monsters have an effect when they're excavated (for simplicity, whenever I mention 'excavating' hereon, that'll also mean milling, unless otherwise stated). Since each of their monsters has an effect of when they're excavated, their monsters also have effects that allow you to excavate, making getting started on your combos from just a single card that much easier. They aim to control their deck, you should think of your main deck as your second hand, as you mostly know the placement of each of the cards on top of your deck, so you can do a controlled mill in order to get where you want to faster and more efficiently.
Without further ado, though, let's get started on the deck list:
Monsters:
(Note: There will be a number beside each monster's description, that is their level)
Sylvan Snapdrassinagon - Snapdrassinagon is basically an extender for milling, as when he's sent to the GY (from deck, hand, or field) you can excavate the top of your deck. He's great for thinning out your deck when you need to, but he can be a bit of a garnet. He's only at 1 in this deck because he's not all that needed, but he can turn things around if you excavate a spell (more on that later).
[1]
Rose Lover - Shouldn't be a surprise, Rose Lover is a great addition to pretty much any plant deck, as when she's in the GY you can banish her to special summon 1 plant from your hand, makes getting your plays off that much easier.
[1]
Sylvan Cherubsprout - Cherub is the main target for Peaskeeper to be special summoned, since he's also a level 1 and when special summoned, you can choose to excavate 1 or 2 cards. His second effect is also decent, letting you special summon 1 level 1 plant-type monster from your deck (once per turn), making going into rank 1 XYZ monsters that much easier.
[1]
Sylvan Princessprout - Arguably one of the more important cards, since both of her effects are really good. You can tribute her, excavate, and then place 1 'Sprout' (meaning only her and Cherubsprout) from your GY to the top of your deck. Her second effect basically just makes it easier to go into XYZ monsters, as when she's excavated you can special summon her and change her level from 1-8.
[1]
Sylvan Marshalleaf - Marshalleaf allows you to excavate 1 or 2 cards when you normal summon him, making him a good starter. When he's sent to the GY, you can target 1 monster on the field and destroy it (not once per turn).
[3]
Lonefire Blossom - Lonefire is a great starter or extender, you can tribute 1 plant monster (which will be himself 99% of the time) to special summon 1 plant monster from your deck.
[3]
Flowerbot - Flowerbot has the effect of when he's sent to the GY, you can draw 1 card and then place 1 card from your hand on the top of your deck, so not only can you get rid of any potential garnets, but you can use him to know what you're going to draw.
[3]
Staysailor Romarin - Romarin is an all-around versatile card that I couldn't recommend enough, since she has 2 good effects that allow you to pop-off. (Quick-effect) You can target 1 face-up plant monster you control and send 1 other plant-type monster to the GY to make sure it can't be destroyed by either battle or card effect once per turn. Her second effect is mostly what you'll use her for though, as when she's sent to the GY, you can send 1 other level 5 or lower plant monster from either your extra deck or main deck to the GY.
[4]
Sylvan Bladefender - Bladefender is a decent card for the most part, mostly because when he's sent to the GY via excavating, you can add him to your hand. His first effect says if he destroys a monster by battle, you can excavate the top of your deck, but I don't know how often you'd be able to pull this off.
[4]
Sylvan Flowerknight - Not much to say about Flowerknight other than he's a decent card, when he's normal summoned you can excavate the top card of your deck. You'll mostly want him for his 2nd effect, though, as when he's sent from deck to the GY, you can place choose to place 1 Sylvan card on the top of your deck.
[4]
Sylvan Guardioak - Guardioak is an alright card and relies less on variables like Lotuswain (a level 5 that excavates based on how many cards your opponent controls) does. Once per turn you can excavate 1-3 cards from the top of your deck, and if he's sent to the GY by excavation, you can choose 1 card from your GY and place it on top of the deck.
[6]
Sylvan Sagequoia - Sagequoia makes it easy to go into rank 7s, as he special summons himself from the hand when a Sylvan monster is sent to the GY, and (once per turn) you can excavate the top of your deck. He's also useful for retrieving your Sylvan spells/traps, as when he's sent to the GY from the deck, you can add 1 Sylvan spell or trap (from your GY) to your hand.
[7]
Sylvan Hermitree - Although you probably won't have him on the field for long (mostly because you'll want to make rank 8s with him), when he is on the field you can excavate the top of your deck AND draw 1 card, making him a prime target for special summoning from the GY (more on that later). When he's sent to the GY you can look at the top 3 of your deck and change the order, making him useful for a controlled mill.
[8]
Snowdrop the Rikka Fairy - Snowdrop is an amazing card for this deck, you can tribute 1 plant monster to special summon herself and another plant-type monster, making it good to get 2 bodies on field. You can also target 1 plant-type monster you control and all other plants you control become that level (so if you special summon her and a level 3, you can then use her effect to make the other card also become level 8).
[8]
Spells:
Mount Sylvania - It's the only field-spell of the archetype, and it's a decent on at that. You can send 1 plant-type monster from your hand or (face-up) field to the GY and then place 1 Sylvan card from your deck on the top. During your opponent's end phase you can excavate the top card of your deck, making it useful to get in something like a Marshalleaf to pop a card.
Sylvan Charity - Sylvan Charity is a card you'll pretty much always want to run 3 of, because it's that good. You draw 3 cards, then if you have a Sylvan card in your hand (which you most likely will), reveal 2 cards (including 1 Sylvan card), then place those cards on top of the deck in any order. If you don't have a Sylvan card in-hand even after drawing, you place your entire hand onto the top of the deck in any order. This card makes it easy to get rid of any potential garnets and control your milling even more, while letting you get card advantage.
One for One - Hard not to put this in the deck, you can send 1 monster from your hand to the GY to special summon a level 1 from your deck, pretty much a must-have.
Foolish Burial - You can swap this out for something else, but you can just think of it as an extender, but
do not use this to mill a card that's meant to be excavated first (ex: if you use Foolish Burial on Cherubsprout, his effect won't go off, since he needs to be excavated first).
Pot of Avarice - Avarice is also a must-have in this deck, as you can shuffle 5 monsters from your GY into the deck (which will be extremely easy in this deck) to draw 2 cards.
Monster Reborn - You don't really need me to explain this, do you?
Traps:
None, this deck list doesn't use any traps (for reasons explained below)
Sylvan Princessprite - Princessprite is an amazing card, not just because she's easy to bring out most of the time. You can send 1 monster from your hand or field (face-up) to the GY and then special summon a Sylvan from your GY, making getting your plays rolling that much easier, and you don't have to detach a material to activate this effect. You can detach a material from her to excavate the top of your deck, BUT if it's a spell/trap, you can add it to your hand rather than placing it on the bottom or top of your deck.
[Rank 1]
Orea, the Sylvan High Arbiter - Orea is another really good card for the archetype, as you can send 1 monster from hand or field (face-up) to the GY to look at the top cards of your deck equal to the level of that monster and place them on the top in any order (ex: if you send Guardioak, a level 6, to the GY by this effect, you can look at 6 cards on the top of your deck). You can then detach a material, excavate 1-3 cards, and then return that many number of cards on the field to the hand (this doesn't target).
[Rank 7]
Alesei, the Sylvan High Protector - You can declare 1 card name and then excavate the top of your deck, and if it's the card you declared, add it to your hand, otherwise send it to the GY. Very good card since you can almost always control what's on top, and even if you don't, milling is still useful. If a card is sent to the GY by card effect (this includes excavating your own card(s)), you can detach 1 material and then target 1 card on the field, place it on either the top or bottom of the deck.
[Rank 8]
Potential Questions:
Why doesn't your deck list use any traps?
The deck is based around excavating and getting their monsters in the GY, spells/traps aren't milled and can prevent you from getting off some of your effects, the less you have the better. To make matters worse, Sylvan traps/spells aren't good, at all, so they have a negative impact on the deck.
The deck has no negation or ways to negate, how does that work?
It does struggle if you can't get some of your effects off, but for the most part it can play through negation if you have a decent hand (which the deck is made with being very consistent in mind, it just is a house of cards). If you want, you can replace something like 'Foolish Burial' and a 'Guardioak' with 'Dark Ruler no More' or something, Ash Blossom can work but chances are most of your copies will be milled.
What is the end-goal/end-board of this deck list?
This deck list is pretty consistent in pumping out monsters on the field (that includes XYZ monsters), it really depends. From what I've played, you'll mostly end on Alsei, Sylvan Princessprite, (possibly) Orea, Draglubion and Number 38. This deck has an insane amount of drawing power so as long as you go uninterrupted or can play through interruptions, you shouldn't have a problem with a decent end board. Feel free to change up the extra deck monsters.