Eccentric Boy (DP09-EN014) - Duelist Pack 9: Yusei 2 Unlimited

When using this card as a Synchro Material Monster, the other Synchro Material Monster is 1 monster in your hand. The Synchro Monster that used this card as a Synchro Material Monster cannot activate its effects, its effect(s) is negated, and is removed from play when removed from the field.