This card seems to do an aweful lot at once.
Its a highly effective CC,
It produces bonewalls,
Its CC synnergies withthe bonewall production ability by further accelerating bonewall production.
That kind of synnergy could allow you to set up a near impermeable shield against anything but gravity or earth (i.e. high hp creatures).
I have to agree that this seems quite OP. Especially the adrenaline combo.
Making the bonewall cost
(forcing the above combo to be a duo) isn't as useful for a fire card since fire decks can use immolate to easily overcome any difficulties. Also, soul catchers make death production much simpler since this creature will be killing things to begin with.
One suggestion I can think of is to make it have a chance to hit any target rather than restricting to enemy creatures. Friendly creatures, enemy creatures, maybe even both players. This fits with the "its on fire" theme since having a flaming creature in your ranks would probably burn your own army.
That at least helps counterbalance the CC power a little bit.
I like Chapuz's idea of linking bonewall creation to creature deaths, but I think maybe it should be slightly harder to pull off...
What do you think of this:
"Deals 3 damage to a random target each turn.
: If this card kills a creature this turn, create 1 bone shield."
It would hit a random player or creature each turn and if you shell out 1
then it will produce one extra bone shield token if its victim dies.
This implicitly makes the creature's bone shield production more effective as the number of creatures in play increases because the chance of hitting a player (your or your opponent) increases harmonically as the number of creatures (additional targets to pick from) increases.
That should help balance out bonewall production a little.
Also, I'm assuming you are having this create singular boneshield tokens...
creating a "bone wall" would add a card to your hand and effectively creates 7 shield tokens
