The goal of this deck is designed to have more versatility than a typical Bruna voltron while still having options for smashing in 1 hit. There is also the option to just repeatedly hit your opponent little by little with lifelink or huge creatures.
Bruna, Light of Alabaster + Traumatize - One of the strongest combos in this deck. Milling 1/2 your deck to overwhelm in 1 swing is absolutely devastating and will end games if your opponent cannot respond to Bruna before the attack trigger goes off.
True-Name Nemesis + Corrupted Conscience - Another amazing combo, True-name gets protection from your opponent while corrupt conscience gives him infect. All you need to do is buff him with cards like Battle Mastery or Daybreak Coronet or even Ethereal Armor to create a devastating blow. Of course, depending on your house rules, this combo may just not be useful. We typically play with 11 infect ourselves - thanks to Battle Mastery + card:corrupted conscious + Aqueous Form + Bruna!
Three Dreams + Bruna, Light of Alabaster - My favorite game ender... period...
Search your library for Eldrazi Conscription + Corrupted Conscience + Steel of the Godhead to swing face with 17 infect, trample, lifelink unblockable. If your opponent gets to block by removing steel, you still have the 15 trample infect power that can be devastating to anything that blocks, which provides great state-based removal.
Another great combo if you are certain they cannot remove unblockable before damage: Battle Mastery + Steel of the Godhead + Eldrazi Conscription - This combo will flat out kill your opponent with 34 (17x2) commander damage. If they somehow remove any 1 aura, you still are inflicting heavy damage.
My favorite stall combination: Entangler + Pariah + Spectra Ward - This combo really isn't all that special, but if i know my opponent can stall the game by preventing combat damage, using Platinum Angel or otherwise controlling the combat flow, i typically grab these if i can shroud Bruna with Diplomatic Immunity or Lightning Greaves or even Swiftfoot Boots. They way this works is preventing any damage to either you or Bruna since all damage will be dealt to Bruna, but she has protection from colors, which means she can only be removed by artifacts, global removal or sacrifice. Entangler is there because you should still block all creatures in the event of an instant-speed removal of Pariah during damage. Losing Bruna from a removal of Sepctra this way is much better than losing the game outright.
Another interesting combo with True-Name Nemesis is Battle Mastery and Celestial Mantle - Being unblockable, if your opponent cannot stop True-name and/or celestial, you will just double or quadruple your life total. This is less potent against multiple players, but you still get to have some fun nonetheless!
Note: In most of these situations, you can replace Steel of the Godhead with Spectra Ward if you know your opponent cannot block with an artifact creature and/or you need general protection even if they can block the damage. It also is worth mentioning that high-removal tables will require the Spectra more than Steel given that pro-colors is extremely valuable while forcing your opponent to use removal spells on Spectra which cam be replaced on every one of your turns and potential each opponent's turns as well.