With a format as wide open as Legacy, it's difficult to play a pure "hate" deck. Ideally, you'd have hateful cards that are still good against a wide variety of decks. Since blue is a large part of Legacy, perhaps one of those cards is Choke.
Chalice of the Void is great against several decks, as is Trinisphere. Those certainly limit your own deck building limits, but restriction breeds creativity, right? Ancient Tomb helps accelerate Chalice and Trinisphere while also giving you a way to not play many one-drops and still be competitive. Green Sun's Zenith is probably the perfect card otherwise, since it can be a Llanowar Elves on turn 1 but basically anything later, including Titania, Protector of Argoth!
Abrupt Decay is a great catchall, and Sylvan Library gives you the card selection and card advantage you need, especially since you're playing a bunch of cards with diminishing returns. Obstinate Baloth helps the Burn matchup and also does pretty well against Liliana of the Veil and Hymn to Tourach.
I'd say this deck might be overreacting to Treasure Cruise and U/R Delver, but if you're looking for something hateful, here you go. Just know that Rolling Spoil might be going a little too deep.
- 1 Deathrite Shaman
- 4 Obstinate Baloth
- 1 Reclamation Sage
- 2 Courser of Kruphix
- 1 Titania, Protector of Argoth
- 1 Dryad Arbor