Mossbridge Troll
Creature — Troll
If this creature would be destroyed, regenerate it.
Tap any number of untapped creatures you control other than this creature with total power 10 or greater: This creature gets +20/+20 until end of turn.
Jeremy Jarvis
Shadowmoor (SHM)
• #123Rulings
The total power of the creatures you tap is checked only when you pay the cost. It doesn't matter if their power decreases, or if any of them have left the battlefield, by the time the ability resolves. Note that you may tap a Mossbridge Troll to help pay the cost of a different Mossbridge Troll's ability.
(wotc • 2008-05-01)
The first ability essentially means that Mossbridge Troll always has a regeneration shield. It retains that shield even if it's used.
(wotc • 2008-05-01)
Rulings
The total power of the creatures you tap is checked only when you pay the cost. It doesn't matter if their power decreases, or if any of them have left the battlefield, by the time the ability resolves. Note that you may tap a Mossbridge Troll to help pay the cost of a different Mossbridge Troll's ability.
(wotc • 2008-05-01)
The first ability essentially means that Mossbridge Troll always has a regeneration shield. It retains that shield even if it's used.
(wotc • 2008-05-01)