Is it possible for a unit to have 0 might in Riftbound?

Ruling: Yes, it is possible for a unit to reach 0 might or even negative might (which is treated as 0 for all purposes). A unit at 0 might still needs to take at least 1 damage to be destroyed.

Sequence: (Example with Master Yi and Smokescreen)

• Unit starts at 4 might
• Master Yi's ability gives +2 might (now 6 might)
• Smokescreen applies -4 might to minimum of 1 (now 2 might)
• Pakaa Cub enters, removing Yi's +2 bonus
• Unit is now at 0 might (4 base - 4 from Smokescreen)

Nuances:

• Effects like Smokescreen that say "to a minimum of 1M" are one-time adjustments, not persistent auras
• If a unit later loses a passive might bonus that was keeping it above 0, it can drop to 0 or below
• Units with 0 might still require non-zero damage to be destroyed by damage
• A unit at 0 might with 0 damage remains alive