There used to be a rule where abilities activated in a previous phase could not be negated in current or future phases, but is that still in effect?
For example, if I use the territory class Gentleness during the preparation, can it be negated in the battle phase?
Gentleness - Clay/Red Territory Enhancement - Place on your clay or red Hero: While that Hero is in battle, protect N.T. humans from discard abilities and negate play abilities.
The rule is still in place, but it is
abilities that have completed are CBI in following phases.
So in your example, the "place" on Gentleness is CBI. It is an instant that has completed in a prior phase. The rest
is not CBI, and can be negated each phase.
You cannot undo anything that
completed in prior phases, that is the rule.