The downsides are very similar to eBay
The 2/3 flying death touch parts of this card make it a great complimentary body for life gain as it will be able to hold off quite a lot of pressure on the board but it does still require it to live
That's a very good advantage, and the fact that it's so cheap to play means you can do a massive amount of setup early in the game, or just a play a big monster and have it get over its summoning sickness before the opponent can do anything whatsoever
But lets not overlook the potential for cheating expensive instant or sorcery spells from the graveyard if youve got ways to put them there so that they can gain flashback for just four mana
Abzan Greasefang 4 Raffine's Informant 4 Greasefang, Okiba Boss 4 Thoughtseize 4 Esika's Chariot 4 Parhelion II 3 Darkbore Pathway 3 Grisly Salvage 3 Concealed Courtyard 3 Temple Garden 3 Bitter Triumph 2 Razorverge Thicket 2 Duress 2 Cache Grab 2 Skysovereign, Consul Flagship 2 Blooming Marsh 2 Godless Shrine 2 Witherbloom Command 1 Sentinel of the Nameless City 1 Can't Stay Away 1 Boseiju, Who Endures 1 Mana Confluence 1 Overgrown Tomb 1 Swamp 1 Takenuma, Abandoned Mire 1 Brushland 1 Sheoldred, the Apocalypse 1 Plains 1 Traverse the Ulvenwald 4 Fatal Push 3 Temporary Lockdown 2 Liliana of the Veil 2 Unlicensed Hearse 2 Kutzil's Flanker 1 Reckoner Bankbuster 1 Duress Abzan Greasefang has also returned to its former glory after the bans