Does the Volibear legend trigger when you play a 4 Might unit directly on Trifarian Warcamp?

Ruling: Yes, Volibear's legend ability will trigger when you play a 4 Might unit on Trifarian Warcamp. The unit resolves to the battlefield and Trifarian Warcamp's passive ability applies the +1 Might instantly, so Volibear only ever sees it as 5 Might.

Sequence:

• The 4 Might unit resolves to the battlefield
• Trifarian Warcamp's passive ability applies +1 Might instantly (no chain, no delays)
• When Volibear's play effect registers the unit as resolved, it sees it as 5 Might
• Volibear's legend ability triggers

Nuances:

• Trifarian Warcamp is a passive ability, not a trigger, so it applies immediately with no chain
• This is similar to how Darius sees himself as the second card played in a turn