During your Main Phase: You can discard this card; this turn, your opponent cannot activate Spells, Traps, Spell/Trap effects, or Monster Card effects when a "Gishki" monster is Ritual Summoned, or when a "Gishki" Ritual Spell Card is activated.
Yes, you activate Gishki Vanity's effect before you Ritual Summon a "Gishki" Ritual monster.
I'm wondering about this card. I'm assuming it means your opponent can't activate spells/traps etc. only at the moment you play a Gishki Ritual as opposed to they can't activate spells/traps for the whole turn after you play a Gishki Ritual ??