I'm "assuming" you are done?
Untap, Remove a Fade counter from Blastoderm, Draw, Attack Mythosx with the Blastoderm... Sorry for the sliver hate, but they are like gnats and beasts just want to swat 'em...
After the attack (regardless of what happens), Play Swamp, Tap all to play Spiritmonger.
BB
Life: 20
Hand: 6
In Play: {Swampx2(T,T), Bayoux2(T, T)}
(T) Urborg Elf (1/1, T: Add G, U, or B to your mana pool)
(T) Blastoderm (5/5, 2 fade ctrs, can't be the target of spells or abilities)
(S) Spiritmonger (6/6, B: Regenerate, G: change color until EOT, Whenever ~this deals damage to a creature put a +1/+1 counter on it)
Graveyard:
RFG:
Spiderman
Life: 20
Hand: 4
In Play:
(T, T, T) Plainsx3
(T) Fellwar Stone (T: add any mana that an opponent's land can produce)
(U) Skyhunter Prowler (1/3, flying, vigilance)
(U) Sensei's Divining Top (1: look at the top 3 cards of my library and put them back in any order. T: Draw a card, then put Top on top on owner's library)
Graveyard:
RFG:
mythosx
Life: 15?
Hand: 6
In Play:
(T) Forest
(T) Island
(T) Plains
(T) Winged Sliver (1/1, all Slivers have flying)
(U) Mnemonic Sliver (2/2, all slivers gain "2: Sacrifice this sliver, Draw a card."
Graveyard:
RFG:
Oversoul
Life: 19
Hand: 3
In Play:
-Forest x3 (T, T, T)
-Vine Trellis (0/4, T)
-Wall of Blossoms (2/4, U, trample)
-Rancor (enchanting Wall of Blossoms)
-Smokestack (0 counters)
Graveyard:
RFG: Elvish Spirit Guide