What are the effects of the three sacred beast yugioh cards?

Yugioh: The Gates of the Dark world question?

• This is a question regarding the yugioh trading card game, my cousin and I where handicap dueling a friend of my cousins and I was using the Dark world deck and the main effects of these cards are disscard effects Like "If this card was discarded by a card effect draw 1 card" anyway, I used a feild spell card called "The Gates of Dark World" this is its effect "All feind type monsters gain 300 ATK and DEF, Once per turn you can banish 1 feind type monster from your graveyard; discard one fiend type monster , then draw one card" I tried to use this effect to discard Silva and specail summond it from the grave yard but my opponent said it wouldn't work because the card effect has three effects (the banish, the discard, and the draw) and that the monsters discard effect would happen between the discard and the draw and the effect of the spell cant be inturupted or the effect would not be resolved. Is this tru because every where i go it says the Gates of the dark world is a great way to use the discard effects? please help.

• Answer:

  sillva still summoning. sillva and all dark world monster's effect is mandatory when discarded by eff, so it active when you have resolve all effect of field spell. example : you active the field spell, then you banish your fiend monster from grave and discard sillva. then you draw 1 card. after you draw, sillva's eff active and special summon it from your grave.