Estinien Varlineau's first ability resolves before the spell that caused it to trigger
Normally his would be a huge deck-building cost, but the deck is actually able to play a very reasonable Mono-Black Midrange sort of game, with elements from Scam and Death's Shadow being drawn together by the powerful new Necrodominance
Moreover, Flareon's appeal extends beyond its in-game utility
Cards cast for their warp cost from hand are exiled at the beginning of the next end step, becoming "warped cards" that can be cast again from exile on a later turn
Season Two on Netflix recently started March 10, and the demand for the cards has been insatiable
Coming and/or Going Discard (sample: Ravenous Rats) I play a permanent, usually a creature, that causes a discard when it comes into and/or leaves play