Earthbound Geoglyph (MZMI-EN052) [Maze of Millennia]

While any Level 10 monsters are on the field, this card cannot be targeted or destroyed by card effects. You can treat 1 Synchro Monster as 2 Tributes for the Tribute Summon of an "Earthbound Immortal" monster. If a Synchro Monster(s) is Special Summoned (except during the Damage Step): You can add 1 "Earthbound Immortal" Spell/Trap from your Deck to your hand. You can only use this effect of "Earthbound Geoglyph" once per turn.