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.