Edison Format · March 2010
This card’s Synchro Material Requirements are "1 Tuner + 1 or more EARTH monsters". (You can use Tuners as "1 or more EARTH monsters", since it doesn’t specify "Non-Tuner monsters").
XX-Saber monsters are also "X-Saber" monsters.
Tributing an "X-Saber" monster is a cost to activate the effect.
You can Tribute a face-down "X-Saber" monster to activate the effect.
You can Synchro Summon this card using EARTH Tuner monsters as "1 or more EARTH monsters."
You can Tribute "XX-Saber" monsters to activate this effect because they are also "X-Saber" monsters.