Legends
Legends is a set of cards from the game Magic: The Gathering. It is famous for being blatantly underpowered on the whole, yet somehow having some of the most overpowered cards in history printed in there as well. It was focused around the new legend mechanic, which made a creature or land unique. (At the time, it meant you couldn't cast that spell if another copy was already on the field; now, the rules are a bit different.)
It was the first set to include multi-colored cards, but for some strange reason, being multicolored was considered an inherent benefit rather than an inherent detriment, as was being legendary. Because of this, they made every multicolored creature extremely weak.
Every.
Single.
One.
(For the uninitiated, having more than one color usually means the card is harder to cast, so this is usually compensated by making the effect stronger. For instance, compare Fires of Yavamaya to Fervor.)
Notable Cards
The following is a list of noteworthy cards from Legends. Since Legends is so old, and I don't know shit about Vintage, this list will be mainly focused on the Legacy applications of the cards.
Wood Elemental
If you know the rules of magic and aren't immediately repulsed by this piece of shit waste of paper, you'll fit right in with the rest of /tg/ when it comes to MTG. Wood Elemental is widely regarded as the worst creature card ever printed in Magic history.
Mana Drain
And on the complete opposite end of the spectrum, we have mana drain. Compare mana drain to counterspell. This card is so strong it was banned in legacy.
Jedit Ojanen
This is a prime example of the fundamental problem with the Legends set. The idea behind this card was that being blue and white AND a legend AND A CAT WARRIOR was all so cool that people would already want to play it, so they couldn't make it good as well.
So they decided on a 5/5 for 7 mana.
THE WHOLE SET IS LIKE THIS.
Shelkin Brownie
THERE IS ONLY ONE CARD WITH "BANDS WITH OTHERS" IN THE GAME.
THIS CARD'S ENTIRE DESIGN IS BASED ON AN EXTREMELY NARROW ABILITY THAT ISN'T EVEN GOOD.
Karakas
Karakas doesn't suck. Not by a long shot. It bounces Emrakul, who is otherwise impossible to deal with, and combos with Mangara of Corondor to wipe your opponent's board. Often seen as a singleton in decks running Knight of the Reliquary. At the time or writing, it's a $100 card.
The Tabernacle at Pendrell Vale
Where Karakas is just a really good card, Tabernacle is borderline broken. And for that reason, it costs (at the time of writing) $450.
No, you didn't read that wrong. Four hundred and fifty dollars.
But yeah, go complain about Jace the Money Breaker some more.
Tabernacle sees play in only a few decks, but every one of them wins with lands, be it manlands, volcanoes, or just dragging out the game until your opponent kills himself.
Chain Lightning
This is a great example of where the intent does not at all match the result. The intention of this card was probably a lightning bolt that your opponent could bounce back to you, and you could bounce back again, etc. until one of you ran out of mana.
The result was... lightning bolt at sorcery speed.
The rest of the card isn't even worth mentioning, since the cost to copy it is RR and very few decks will have RR open when you cast it. 99 times out of 100 this card is just a lightning bolt at sorcery speed. It's not a bad card (quite the contrary, 3 damage for 1 mana is great), it's just designed all wonky.
This is a legacy Burn staple, and in conjunction with several other spells allows the deck to run an effective 16 lightning bolts.
Moat
In the vein of Tabernacle, this is another extremely expensive niche card. Clocking in at $350, this deck shuts down most aggro decks for only 4 mana. The only frequently used creature in the Legacy format that has flying is Vendilion Clique, so Moat does work most of the time. It's only really used in Enchantress decks.