RD/KP02-JP020 ドラゴンズ・ストライカー Dragon’s Striker
Level 4 EARTH Dragon-Type Effect Monster
ATK 1300
DEF 200
Requirement: If there is a face-up “Dragon’s Keyperson” on your field, you can activate by sending 1 card from the hand to the Graveyard.
Effect: Choose 1 face-up monster on your field, during this turn, that monster gains 400 ATK, and its attack pierces (When a Defense Position monster is attacked, inflict battle damage based on how much higher the ATK is than the DEF)

Source