Also note that if the opponent card facing your card with steroid has whip, it will absorb part of (or entire) steroid bonus and temp. add it to that card's opponent.
For example:
EnemyCard1
whip 5
YourCard1 YourCard2 YourCard3
steroid 10 steroid 3
So suppose that YourCard2 combines with another card. All cards you own that have steroid ability will be triggered and permanently increase the attack point of your cards. So YourCard3's attack will permanently increase by 3.
However. YourCard1 will only increase its attacking power by 5 even though it should increase by 10 because the enemy card facing YourCard1 (EnemyCard1) has whip ability, meaning any attack rise (steroid, viagra, etc) will be temp stolen. So YourCard1 will increase its attack by 5 and the other 5 is stolen by EnemyCard1 to boost its attack up by 5 points for its one upcoming turn. Once that turn has completed, the attack boost of 5 stolen by EnemyCard1 will expire. The 5 stolen attack points will not return to YourCard1.