Beaming Blade

Once per Turn Action -

: Attack

If a yellow card has been put into your hero's soul this turn, this gets +5

You may still attack with Beaming Blade even if its attack is 0. The defending hero may still defend the attack. If Beaming Blade does not deal damage to the target during the defend step of combat, it does not hit.
This is a static ability. If you attack with Beaming Blade, then put a card into your soul, Beaming Blade will get the +5.
Putting two or more cards in your soul during the same turn will not give Beaming Blade an additional +5.
When the current turn ends, Beaming Blade loses the +5 until the next time a card has been put into your soul during a new turn.