I'll let you choose. Both choices require the resolution to sacrifice oneself.
[AUTO](RC):[Soul Blast (1) & Retire this unit] At the end of your turn, you may pay the cost. If you do, your opponent chooses one of his or her rear-guards, and locks it. [AUTO](RC) Generation Break 2:[Counter Blast (1)] When this unit attacks, if you have a vanguard with "Chaos" in its card name, you may pay the cost. If you do, your opponent chooses a card from his or her hand, and he or she may put it on his or her (RC) as a locked card. If he or she did not, you draw a card, and this unit gets [Power]+10000 until end of that battle.