mtg whenever you discard a card draw a card Scrounging Skyray (Aetherdrift) If You Discard A Card,

701.25d: An ability that triggers whenever a player surveils triggers after the process described in rule 701.25a is complete, even if some or all of those actions were impossible.

9 Plains By Stephan Martiniere - $34 Magic Premiere Shop 2005 #287 (Japanese) This fantasy-style design from the Japanese Magic Premiere Shop series, distributed via selected game stores back in 2005, is sure to be recognizable to fans of Stephan Martiniere

Multiple instances of toxic are cumulative

Being able to either send three to each opponent (or more, with damage doublers!) or instead sweep away mana rocks and equipment is right what these decks want

Finally, Dredge might also side in Abrupt Decay or Leyline of Sanctity for protection from dedicated Burn decks, though getting it in the opening hand is essential.