// Target opponent loses half his or her life, rounded up.
this.getSpellAbility().addTarget(new TargetOpponent());
this.getSpellAbility().addEffect(new BloodTributeLoseLifeEffect());
// If Blood Tribute was kicked, you gain life equal to the life lost this way.
Effect effect = new ConditionalOneShotEffect(
new BloodTributeGainLifeEffect(),
KickedCondition.getInstance(),
"If Blood Tribute was kicked, you gain life equal to the life lost this way");
this.getSpellAbility().addEffect(effect);
}