have no time to write this in trigger tags but
event - perodic 0.02 - 0.03 (depends on what you want)
condition - none
actions -
to make this MUI, do the normal MUI for each bla ...
then animation vertex coloring and in transparancy you must make some kind of math like value/value or you just have an variable
and your unit must be indexed
also if you want the variable thing after for each bla you do
set variable test real/integer = test real/integer - value
so it will be lowerised each time and if you want it smooth over 0.5 second, make it a very small value