Making the bonus temporary should be good to prevent the worst of abuses... Chimera might still be a an issue though.
(Fractal spark or fractal photon + this + chimera)... This is a trio, of course, so that will make it tricky to pull off.
Depending on how and when the loss of the bonus HP occurs, this may end up being somewhat of a niche card or it may be a useful anti-CC buff.
If the HP were to disappear at the start of next turn, this card could be very useful as an anti-CC buff.
Lastly, is damage deducted from bonus HP first or regular HP first?...
Consider, for instance: a player has 2 of these in play. They then play a Giant Frog (5|3 base) it gets bumped to a 9|7 for 1 turn... The player then casts Rage Elixer, yielding a 14|2 ...
Now, if the bonus HP get chewed up first, then after this turn, the frog becomes a 10|2... if the regular HP are used first, it dies.
Thats not necessarily going to make it OP though, since the above scenario requires at minimum
-A duo
-(2*6
+ 2
+ 3
) = 17
-4 card combo
Thats a lot of work for a 10|2 creature when you can get better for less with Seraph SoW
This could be modified to a nymph and mitosis scenario
-Duo
-(2*6
+ 2
+ 5
+ 9
) = 27
setup
-After setup: (2
+ 3
) = 5
for each 10|2 creature
-5 card combo setup
The first scenario isn't really OP (considering the output to cost ratio of other fractal or mitosis combos with fire…)
The second scenario will be quite potent once its gets rolling, but the large initial investment and combo size should balance that out.
