Perdition Dragon, Tinder Spear Dracokid

:Forerunner (When a unit of the same clan rides this unit, you may call this unit to ) : 1 When an attack hits a vanguard during the battle this unit boosted ([Boost]), if your vanguard is [Legion], you may pay the cost. If you do, retire all of your opponent's rear-guards in the same column as this unit, and put this unit into your soul.