This deck is based on sending your dragons to graveyard with the dragon ravine effect and bringing them back with the effect of arkbrave dragon and return of the dragon lords.
I don't know if this deck is meta level(probably not), but it is very easy and funny to use.
You can either go first to put goliath on the field and locking your opponent's extra deck( and yours, but it don't matter), or going second to try an OTK or pressuring your opponent with powerful dragons.
Dragon's mirror is not essentially used to bring alternative ultimate, but you can do twin burst with it.
Your main extra deck monster are: hieratic seal of the heavenly spheres, blue-eyes spirit dragon and azure-eyes silver dragon, because them can make a strong field presence, by bringing other big dragons or negating/returning your opponent's cards.
In general, this deck is really funny to play, and the weak point of the deck is heavy backrow decks, like altergeist and true draco, but you can win against them because of the effect of dragon spirit of white and arkbrave dragon, that both banish spell/traps on the field(and they are my favorite cards in this deck).