Magic: The Gathering's newest expansion set is Time Spiral Remastered, and this draft-only set is getting ready to cater to experienced and savvy players who can handle a huge variety of complicated cards. After all, it's based on the original Time Spiral block, which was also geared for veteran players only.
As for what kind of tribes, mechanics, keywords and themes will be in the Time Spiral Remastered draft set, it might be faster to list what won't be in it. This set features many complex moving parts and diverse abilities from across the entire game's history.
Mighty Morphing Blue Creatures of Time Spiral Remastered
The Morph mechanic is a classic, appearing a few times in both pre-Modern and Modern eras, such as in the Khans of Tarkir block (along with its Manifest and Megamorph variants). Morph was also in the original Time Spiral, and naturally, it returns in Time Spiral Remastered. All kinds of creatures are morphing, and they often have an effect when they turn themselves face up to disorient and sabotage the enemy.
Brine Elemental can be cast as a 5/4 for {4}UU, but if it's cast as a 2/2 Morph creature and turned face up, it will force each opponent to skip their untap steps. Morphing this after the opponent attacks is a great way to shut down the opponent on their next turn, preventing them from attacking since all their creatures are tapped (and their lands stay tapped, too).
Vesuvan Shapeshifter is a complex creature, combining Morph and Shapeshifter into one package. When it hits the battlefield or is turned face up, it can imitate another creature. It can also turn itself back face down during the upkeep. If there are no creatures worth copying, Vesuvan Shapeshifter's caster can play it as a 2/2 Morph creature to bulk up their board presence, waiting until a good creature comes along and Morph the Shapeshifter to imitate it. Then, if an even better creature arrives, Vesuvan Shapeshifter can turn back face down before Morph to copy the new creature. Not every Shapeshifter in the game can change so often; most are stuck with the first form that they assume.
Timebender is a tiny 1/1, but it Morphs for cheap, and it can remove two time counters from another card or add them instead. This can be done to speed up a friendly Suspended card and get it sooner, such as Ancestral Vision, or slow down the opponent's Suspend card. Timebender can also remove time counters from an opponent's creature with Vanishing, and make them go away much sooner (or keep a friendly Vanishing creature around longer). This card is deceptively complicated, but effective.
Shaper Parasite is an Illusion that can turn face up to boost and lower another creature's power/toughness. It can grant +2/-2 to an evasive friendly creature to hit for extra damage, or grant +2/-2 to a small enemy creature to kill it. This card can also grant -2/+2 to an opposing creature to lessen the damage dealt, or give -2/+2 to a friendly creature to save it from lethal damage. This card is also deceptively complex.
Shadow, Split Second and Much More in Time Spiral Remastered
In Time Spiral Remastered, blue mana is making heavy use of the Morph mechanic, many diverse counterspells and the Merfolk tribe, but this color can do much more. Many odds and ends appear in this color too, such as Wipe Away, a merciless bounce spell that can target anything, even lands. Wipe Away has Split Second, meaning no other spells or abilities (aside from mana abilities) can be put onto the stack while Wipe Away is on the stack. This means no opponents can counter or respond to Wipe Away, allowing the card to resolve as it pleases. Other colors are known for having Split Second, too.
Think Twice makes it clear that flashback will be common in this set. It's a graveyard-based ability that can get some extra value out of the card by casting it for a second time. Think Twice is a fine way to restock the hand in a control deck, often being played at end of turn if the opponent didn't do something that merited a response. Pongify is the blue Beast Within, destroying a creature and replacing it with a 3/3 green Ape token that has no abilities.
Then, Time Spiral Remastered offers cards with Shadow, meaning these creatures can only block or be blocked by other creatures that also have Shadow. Most often, Shadow creatures are small but crafty attackers that deal damage bit by bit, but they can also be drafted to block an opponent's own Shadow creatures. Infiltrator il-Kor is a 3/1 that not only has Shadow, but can also be suspended for {1} if paying {4}U proves difficult.