Does Volibear's legend trigger when a Weaponmaster unit becomes Mighty after equipping a gear, or when Rengar becomes Mighty after being designated as an attacker?

Ruling: Volibear's legend does not trigger in either case because the units are not Mighty at the moment they are played.

Sequence:

• When a unit is played, Volibear's legend checks if it is Mighty
• For Weaponmaster: The unit becomes Mighty only after the "When You Play Me" trigger resolves (after the legend check)
• For Rengar: The unit becomes Mighty only after receiving the attacker designation (after the legend check)

Nuances:

• Passive abilities (that aren't dependent on designations) become active just before a unit is considered "played"
• Examples of units that would trigger Volibear: Point Draven (becomes Mighty via passive before being played) or a 4 Might unit played to Trifarian Warcamp