Valgrowth of Expansive Summer

[AUTO](RC):When this unit attacks a vanguard, if you have a grade 3 or greater vanguard with "Estacion" in its card name, this unit gets [Power]+5000 until end of that battle, at the end of that battle, retire this unit, and draw a card. (This effect is mandatory) [AUTO]:When this unit is put on (GC), if you have a Blast token, choose one of your opponent's rear-guards, and that unit's original [Power] becomes 5000 until end of turn.