Frosty Torchbearer Frost Novas the towers to shut them down for 10 seconds while stunning the DG's. then he Ice Rains them for damage and an attack speed debuff. He then auto-attacks Sedna while waiting on his Deep Freeze to counter her Heal and lock her out of it for awhile. it will also get a 2x Shatter for good measure.

Torchbearer's partner is Unclean Beast. he opened the fight with Foul Grasp on Sedna to make sure she couldn't pounce or silence the Frost Nova. He finishes off Sedna with a Venom Spit once she starts running after the Deep Freeze hits. Rook goes down in a pile to the 2on1 after Sedna dies. the towers were frozen for the entire encounter. Torch and Beast are gone before the Frost Nova wears off. 

Prolly a Angelic Fury/Mines Regulus and a Frost or Hybrid Torchbearer. You can both hide behind Reg's mines and take out Rook's towers from a distance. Torchbearer would also need to AoE minions before they come into the mines, so that the mines stay up in the event Sedna wants to push, giving you both nice experience in the process. If Sedna pushes, Reg and Torch immediately focus fire on Sedna. If Sedna tries to heal, Torch interrupts. GG.

It's fairly easy to predict. Even if it goes through, it has a seven second recharge.

Rook, well, if he's the typical tower Rook, all he's going to do is sit back, drop towers, and occasionally roll a boulder. It's not exactly hard to dodge a boulder roll unless Rook gets up close, which he wouldn't want to because he'd get raped by mines, TB AoE, and extremely high DPS from Reg's Angelic Fury bolts. Sedna can throw a heal out, but, that's only once every seven seconds.

Simply put, if either of them wants to damage you, they're going to have to get up close, and that's NOT something they want to do when you've got mines and possibly Circle of Fire.

Level 5 or higher, 2 QoT's with a minion/defense build.

I say nay.

I've interrupted my fare share of heals with Deep Freeze. Just gotta turn off music, listen for the annoying heal sound and have Deep Freeze already selected and over Sedna