It's not immolation on a stick. It can only self-immolate, you know in that case when the opponent is rushing and he has no cards in his hand and you have no use of Pyro Tank anymore.
I know what you mean about cards don't need existing abilites, but releasing 12 tanks with unique abilites is quite challenging, and as you may see I didn't succeed to make all 12 tanks unique, but I'm still working on it. However, I'm glad that some of my tanks got good words and that's what encourages me to continue. *Steve Jobs smile*
The Tank wasn't unequivocal about who immolates who
That's not a big fault if the idea is not 100% original (it's nearly impossible in 12 card in a row), but if you take "Fiery" on a card without explaining what's Fiery is a very bad idea. Yes, there's some example for not explaining (Chimera), but in the most cases, you can know the usage of 1 card without knowing the others (as like Armagio|Sapphire charger|Immortal|Vampire says the name of the ability and the explanation). That's a newbie help, so you doesn't have to read a rulebook to know the rules till the beginning.
My post was about to reduce the wording and to prevent this "Fiery" and "Cremation" thing. You can say that "0: Sacrifices Fire tank and you gain 5|7
or "gains +1|0 for every 5
you own " and that will be correct.