Dem auras.
Due to MBC being so popular in the last tournament, the side has a lot more to deal with it.
The single target kill spells (and burn spells) don't matter as much because most of the creatures have Pseudo Shroud (or hexproof for all you new keyword lovers). The big issues come in forms like Geth's Verdict. This is why we like Dawn Charm. Replacing the Fog effect cards from the side and adding these, we get more utility and still get to keep our Fogs.
Discard (specifically Hymn to Tourach in paper pauper) gets annoying, and really slows us down. This is the reason for the addition of the lovely Basking Rootwalla. It can be played through the discard so we get card advantage from a disadvantage.
We also don't want to get beat down from the random Gurmag Angler that some lists pull out, or we just want easy damage. So the single Order of Leitbur can do a lot of work. It can also pump itself if we need it to, or take out annoying problems such as card:kilin fiend thanks to its first strike.
Usually the mirror match is a race, and becomes "Who went first?". The Standard Bearers are a must to slow down that race. They also help against stompy and infect decks.
Rounding off the sideboard are the lovely Benevolent Unicorns to help against those annoying red decks.
That takes care of the main threats in the meta due to the deck being strong against tron and familiars in the main from the Lush Growth. Blue control would be a problem depending on what they choose to counter. And a more token beatdown would also be annoying if we can't get some lifelink out. However, these decks weren't very popular in the previous events so there isn't too much concern there.
