Do units played from hand during showdown gain assault/shield bonuses, and does playing Rengar (3 might, assault 2) trigger Volibear's legend ability?

Ruling: Units played from hand during showdown will gain assault/shield bonuses because a cleanup occurs when the permanent is played, assigning attacker/defender status and applying the bonuses at that time.

Sequence:

• When a permanent is played during showdown, a cleanup occurs
• During cleanup, units at the battlefield without attacker/defender designation gain the same designation as their controller
• Assault/shield bonuses are then applied based on that designation

Nuances:

• Playing Rengar (3 might, assault 2) as an attacker does NOT trigger Volibear's legend ability because Rengar enters as 3 might and only becomes 5 might after cleanup
• In contrast, playing a 4 might unit at Trifarian Warcamp DOES trigger Volibear because Trifarian Warcamp applies instantly as the unit enters, not requiring cleanup