Haldir goes very well with other cards on this list like Galadhrim Ambush
The good news is that in the right deck, Unpredictable Cyclone is still very powerful when played fairly, allowing you to cast expensive spells for just the one or two mana it costs to cycle a card while also getting around normal timing restrictions by allowing you to cast creatures and sorceries during your opponent's turn (if you cycle into them)
If you can play Rest in Peace in your sideboard, make it happen
When the ring was found, the price for those same boxes immediately dropped by 20%, proving the bubble was tied to that single chase card
The same is true for counters that change a creature's power and/or toughness
FromTheShire: With Domain being a sizeable portion of the current Modern meta in addition to the random inclusions in other decks like Omnath, Locus of Creation I expect this to see some testing in Burn sideboards