You bring up comparison. That's good.
Fireeater is 2 
for 0|5 and 
ablaze
Fire spirit is 2 for 0|2 and ablaze
Forest spirit is 2 
for 1|1 and 
growth
Lava golem is 5 for 5|1 and 
growth
Sapphire charger is 5 for 4|5 and momentum
When compared to fire spirit, it requires a duo cost for only 3 extra hp. 5hp does make a difference, but lightning is the most common CC card in PvP, so it's not that large of a difference. Does it really justify the duo cost?
When compared to forest spirit, both of them require duo cost growing, but growth is better than ablaze, and forest spirit starts out with 1 extra attack (and in 2 turns will be just as sturdy).
Lava golem is 5 instant attack for 5 , along with the ability to grow. It's also able to come out much easier with immolation and much faster than fire eater.
Sapphire charger costs 2.5 times, but it would take a fire eater at least 5-6 turns along with constant (so costs balance out along with turns) to deal the same damage the charger did, and charger ignores shields.
Good points, but consider the following:
Life's creatures cost -1
in general (look at Horned Frog or Cockatrice as examples here), so Fire Spirit's "true" cost is 3
and not 2
.
About Ablaze, it is indeed somewhat worse than Growth (since it increases only attack and not health), however let's take a look at both Fire Spirit and Fire Eater:
* Fire Spirit hits early the field, but it doesn't deal damage and it has fragile health, so how are we going to cover these two disadvantages? The answer here lies to Blessing IMO. Blessing gives a boost to both its attack and defense, making to strike right away when it hits the field and grants it greater CC protection. Soon, it will grow strong. This combo is not so difficult to balance if you consider the vast amount of
/
synergies, starting from Seraph's Divine Shield and Ragepotted Archangels to the well-feared FireStall, let alone the fact Blessing can be combined well with other
creatures too.
* Graviton's upped RagePot combo can be fullfilled unupped too with the following way: Graviton Fire Eater + Momentum + Rage Potion. I know what you probably think, "3-card comboes are bad, really bad!!!", however consider the following once more:
1) Momentum is
and Rage Potion is
, so they are both in-element with Graviton Fire Eater.
2) Momentum combines well with every creature, so FireEater + Momentum is not a forced combo.
3) Rage Potion can also be used as CC, so FireEater + RagePot is not a forced combo either.
4) When it works, this combo grants an 6|1 attacker who can bypass shields and who can still grow for more damage.
These are just examples; there may be even better comboes out there...
