Out of all the Magic: The Gathering formats that are out there, Legacy is very similar to Vintage in that, in recent years, we'vee seen a resurgence of these older formats. Wizards of the Coast has made a real effort to add some more cards to these formats through Modern Horizons and Commander Legends sets.
The latest of these sets is Commander Legends: Battle for Baldur's Gate, which takes inspiration from Dungeons & Dragons and the Forgotten Realms setting. While it mostly caters to Commander and multiplayer formats, there are a few cards that could find a home in various Legacy Decks. So let's have a look at some of the cards that are most likely to see some actual play in the Legacy format.
5 Ascend from Avernus
This is a white sorcery spell that costs X generic mana and three white to cast. After playing it, you get to return all creature and planeswalker cards with mana value X or less from your graveyard to the battlefield, and then exile this card afterward.
This could be a pretty decent addition to the Death and Taxes deck, at least as a sideboard card. Given that most of the creatures in this deck have a low cost, this could potentially bring a ton of creatures back into the game for you. With Aether Vial there to help you flood the board with creatures in the early game, this could be an ideal answer to board wipes.
4 Bramble Sovereign
A green Dryad creature that costs two generic and two green mana, Bramble Sovereign is a 4/4 with a pretty cool ability. Whenever another nontoken creature enters the battlefield, you may pay one generic and one green mana. When you do, the owner of that creature creates a token that's a copy of said creature.
Even though he's not an Elf, Bramble Sovereign could find a decent spot in a Legacy Elf deck. Elf decks usually have rather cheap creatures, but copying some key creatures for only two mana could still give you an edge. And, of course, managing to copy a Craterhoof Behemoth will usually spell game over for your opponent. Bramble Sovereign has been in Legacy for a while thanks to its debut in Battlebond, but maybe Battle For Baldur's Gate will draw more attention to its potential in the format.
3 Altar of Bhaal
An artifact Adventure card, Altar of Bhaal contains an Adventure sorcery called Bone Offering that you can play first. Bone Offering costs two generic and one black mana, and it creates a 4/1 black Skeleton creature token with menace. Altar of Bhaal itself is an artifact that costs one generic and one black mana. If you pay two generic and one black mana, tap it and exile a creature you control, you get to return a target creature from your graveyard to the battlefield.
Even though it might look rather slow compared to other spells that the Reanimator deck uses, this card can still find some use. While a Reanimator deck will probably relegate this card to the sideboard, a deck such as Death or Taxes might find room for it in the main deck, since most of its creatures are very cheap. Exiling creatures that are no longer useful to bring back your big threats to the board could prove troublesome for most opponents.
2 Displacer Kitten
This adorable 2/2 murder machine is a Cat Beast creature that costs three generic and one blue mana. Its main ability is called avoidance, and it states that whenever you cast a noncreature spell, you have to exile up to one target nonland permanent that you control, then return that card to the battlefield under your control.
Displacer Kitten could find a spot in the 8-Cast deck, since most of the cards in this deck are artifacts that will trigger Displacer Kitten. Most of the creatures in the deck have "enter the battlefield" effects, so flickering any of them will give you extra bonuses. Flicker any of your artifacts with Kappa Cannoneer on the table to pump and make him unblockable, do the same for your Thought Monitor to draw two more cards, and so forth.
1 Nautiloid Ship
An artifact Vehicle card, Nautiloid Ship costs four generic mana and is a 5/5 with flying and Crew 3. When Nautiloid Ship enters the battlefield you get to exile target player's graveyard. Whenever this Vehicle deals combat damage to a player, you may put a creature card exiled with Nautiloid Ship onto the battlefield under your control.
This is a card that could find a place in pretty much any creature-focused deck in the Legacy format. Death and Taxes could make good use of it as a sideboard card against Reanimator decks, or any other deck that focuses on graveyard interactions. The fact that you can play creatures that you have exiled with Nautiloid Ship afterwards is the cherry on top. Even Elf decks could also make good use of this card, especially since they don't really have any answers to Reanimator decks except for Endurance.