Often I get the question if Burn in Legacy is a viable deck, considering how expensive Legacy is and how cheap Burn is.
I generally say that it’s nowhere close to Tier1, but you do have some good pairings and even a somewhat 50-50 MatchUp against Delver decks.

Legacy Mono-Red Burn Deck List – Phil_1987 (5-0 MTGO League)
Land (20)
I always welcome new cards to Legacy, and Chandra’s Incinerator is no exception.
Thanks to Rift Bolt, you’re able to drop this Elemental as early as turn 2 with the help of another 3 damage burn spell.
While some decks with Swords to Plowshares will easily handle the Chandra’s Incinerator, other decks, namely Delver decks, will have a tough time against it.
A 6/6 Trample on Turn2 is no joke and don’t forget about Fireblast which let you cast this card for 2 mana without any additional help.
This card won’t dramatically change Burn match-ups, you’ll still be an underdog against combo decks, be fine against fair decks and be very good against Lands decks.
If you’re looking for a cheap way to enter the wonderful Legacy format, Burn is an okay cheap solution.