Out of three possible Opera encounters, I would say this is probably the one best suited for warrior tanks. It requires a lot of coordination from the raid, and good interrupts, plus dispellers.
This is a two tank encounter. If there’s only one warrior tank, she should be on Julianne duty for interrupts. If you have more than one warrior (or none), the better geared tank should be on Romulo.

Julianne
Phase 1 is over quickly. Julianne is a cloth-wearer and doesn’t have much health. Cue the Romulo tank who has to stand ready to use Thunderclap, Demo Roar or Consecrate to immediately pick up Romulo. It is best to tank him against the wall by the stage entrance. You want your back against the wall to avoid his knockback. He deals a lot of physical damage, so having high armor will help here. If Daring is Purged/Dispelled once up, you shouldn’t have too much trouble. It also helps to have a shaman, druid or paladin remove the poison he applies.
Phase 2 ends with Romulo dead but remain by his corpse. R&J will show up together. Both tanks need to be ready to pick up their targets immediately, by using the usual methods of AoE threat and then start off with a high threat move. You especially do not want Romulo in the raid, he is painful.
Julianne’s health should go down a lot faster than Romulo’s, so it is entirely possible that a DPS stop will be called. If that’s the case, make sure that you as J-tank remain on top of her aggro list, only use Auto-Attack, and Shield Bash her heals. Here’s where having MT frames really helps so that you can closely watch the targets’ health. You do not want them to die outside of that narrow five seconds window. If your raid can time this procedure correctly, those two are very manageable.
Lootwise, aside from the Eternium Greathelm any Opera boss can drop, there’s really only one thing worth mentioning: Romulo’s Poison Vial. If all your physical DPS already has it or are hit-capped, it can make an interesting threat trinket for a trash tanking set.
