Summon: Magus Sisters

A chapter ability doesn't trigger if a lore counter is put on a Saga that already had a number of lore counters greater than or equal to that chapter's number. For example, the third lore counter put on a Saga causes the chapter III ability to trigger, but chapters I and II won't trigger again.

"Shield" is not an ability that creatures have and shield counters are not keyword counters. If a creature with a shield counter loses its abilities, the shield counter will still protect it as normal.

Removing a shield counter when a permanent would be dealt damage or destroyed isn't the same as regenerating that permanent.

The random choice of mode for Summon: Magus Sisters's chapter abilities is made before targets are chosen.

Saga creatures have two sections to their text boxes. The first section, above the type line, contains their chapter abilities, and the second section, below the type line, contains any other abilities (or italicized flavor text). Any abilities in the latter section aren't chapter abilities and apply no matter how many lore counters are on the creature.

If a permanent with a shield counter is dealt unpreventable damage, that damage will be dealt and a shield counter will still be removed.