With the banning of Goyo Guardian, we Asia format players are screaming for a viable substitute.
That lone Brionac won't do you good most of the time when you need brute force.
So, for us, Asian players, some official choices include :
1. Gaia Knight, Force of the Earth
While lacking of an effect, he makes up with his attack ... well sorta. For a Lv6 Syncro, 2600 isn't really that bad, problem was that Goyo was bigger and had a broken effect. With Goyo gone, Gaia is the biggest Lv6 beater you got.
2. Iron Chain Dragon
With a decent 2500 attack and for the fact that his a dragon, this guy was a staple in Dandy decks until they dropped Ryko completely. But with so many cards getting limited to 1 at the moment, this dude's effect may come in handy (sometimes). Imagine dropping that lone Gateway or Kalut of the top of the deck.
3. Splendid Rose
At least this card is a generic syncro. Splendid Rose has only 2200 attack and can only activate his//her effect when you have plants. So, you should only play this when you play Glow Up and Spore. While that sucks, this card can potentially deal 3300 points of damage in 1 turn, that together with the fact that Warnings are run so much, this card can be use to push for game. (sometimes)
Sadly, those may be the only options you have for that empty Lv6 spot Guardian once so firmly sat.