At the start of your Main Phase 1, if you control no Spell/Trap Cards: You can Special Summon this card from your Graveyard. You cannot Special Summon another monster(s) the turn you activate this effect. While this card is face-up on the field, it cannot be Tributed, except for the Tribute Summon of a "Steelswarm" monster, and cannot be used as a Synchro Material Monster.