Does the pigs lost soul negate the bronze laver?
It does not prevent the whole ability, but it does prevent the draw.
Lost Soul (Pigs) - Luke 15:15-16 - LS Prevent all draw abilities, except on Heroes.
The Bronze Laver - Exodus 30:18 - A Upon activation, reveal any number of evil cards from hand. Place them beneath draw pile and draw an equal number of cards.
The Pigs LS does prevent all drawing that isn't on heroes, and that includes artifacts. It does not prevent underdecking cards, which is the "cost" part of Laver, but it does prevent the drawing cards, which is the "benefit". You may pay the cost without receiving the benefit, so if you activate this artifact you may still underdeck but you may not draw.
Note that this is actually beneficial to certain decks, but if it were to happen unintentionally (where a player activated Laver, placed cards beneath deck, and then wanted to draw), they would just be out of luck. Everything else was legal and would stay, they just wouldn't be allowed to draw the cards they wanted, since that part of the ability is prevented.
(Note on the note: In a friendly game, I'd allow it to be taken back, but you don't have to allow it and it shouldn't be that way at tournaments in general.)
