It can't be denied that the introduction of Synchros has not been successful so far—the new summoning mechanic still takes too many resources compared to the value it can ultimately bring.
There already is a viable X-Saber Deck, but this one, rather than focusing on the newly added XX-Saber Fulhelmknight and XX-Saber Boggart Knight, takes a different approach, taking advantage of the various support for Normal Monsters that is present in the game.
If you have exactly three Normal Monsters in your Graveyard, you can banish two and Special Summon Knight of the Red Lotus from your hand; you can send X-Saber Anu Piranha or Galaxy Serpent from the Deck to the Graveyard with Painful Decision or just use them as material for a Synchro Summon.
Once per turn, Knight of the Red Lotus can Special Summon a Level 4 or lower Normal Monster from the Graveyard; you can Special Summon Galaxy Serpent and then Synchro Summon Stardust Dragon.
This Spell Card allows you to Special Summon a Level 4 or lower Normal Monster from your Deck, it’s a great way of getting two monsters on the field on your first turn and bring out XX-Saber Hyunlei; keep in mind that you can only activate Unexpected Dai if you control no monsters.
Paleozoic Canadia is here for protection, it's a great card against some of the current most popular decks like Fur Hire.
You can Special Summon Canadia from the Graveyard as a Level 2 monster by chaining it to a Trap Card on the field; Canadia can then be used for protection or as Synchro Material.
This Continuous Trap can Special Summon a Normal Monster from the Graveyard in Attack Position, you can use it for protection to avoid OTKs or to get a monster on the field for a Synchro Summon.
The best—and only—generic Level 8 Synchro Monster, Stardust Dragon can negate the effect of any card that would destroy something on the field by tributing itself and then come back during the End Phase of that turn.
Stardust has a decent amount of ATK and an effect that provides protection against cards like Treacherous Trap Hole and Vampire Kingdom, but it's weak against Spellbook of Fate, Amazoness Onslaught and Vampire Vamp.
When it's Synchro Summoned, Hyunlei can destroy up to 3 Spell/Trap Cards on the field, so it's essentially able to clear the opponent's backrow by itself.
You can Special Summon Hyunlei using X-Saber Anu Piranha and Galaxy Serpent or even two Paleozoic Canadia and Galaxy Serpent.
This Skill guarantees a starting hand with at least a Monster, a Spell and a Trap Card, it’s great for consistency.
Wiz, Sage Fur Hire's “once per turn” negation can be an issue as it can prevent you from activating Unexpected Dai. Paleozoic Canadia is very important as it can slow down the opponent while you are setting up the field.
While this may look like an easy matchup for this deck due to the fact that X-Saber Hyunlei is able to destroy Amazoness Onslaught together with whatever the opponent has to protect his monsters, there is one glaring issue: Amazoness Queen; this deck has literally no way of getting around the protection from destruction by battle.
Overall Amazoness should not be too difficult to handle, but, once Queen is on the field, you are going to have to win by decking out the opponent, which should be possible if Amazoness Princess searched Onslaught and then Special Summoned Queen.
Vampire Vamp is probably the biggest threat as Vampire Kingdom can be destroyed by Hyunlei and its effect could still be negated by Stardust; after losing the Field Spell, Vampires are a lot less threatening, but any monster with 2000 or more ATK is an easy target.
Masked HERO Anki is able to get over Stardust Dragon and Hyunlei naturally, so flipping it face-down with Canadia and then attacking is the only way to get rid of it.
Paleozoic Canadia is again crucial because it can prevent the opponent from switching out U.A. Midfielderfor any of the high Level U.A. monsters, which are difficult to handle. U.A. Penalty Box is another issue because Stardust has no protection against it, but you can still destroy it and the Field Spell with Hyunlei.