(VX) Skill that buffs stat for 1 turn, (pac engine)

So, I have an idea for a skill "Shield" that acts like the defense action, but can target either just the user, or a friendly ally, but buff the users Defense (or other applicable stat/stats) by a specified amount for the duration of 1 turn of battle.

I am using the Pac Engine, and it has some useful capabilities, including these under PAC Item, Skill, Equip Addons:

Code: [Select]

# <target temp param: +x>
# <target temp param: -x>
# Placed in an item's or skill's notebox, these give a temporary boost or fall
# to the specified parameter of the target of the skill or item until the end
# of the battle. Replace param with maxhp, maxmp, atk, def, spi agi, hit, eva,
# cri and odds (and dex or res if you have the scripts). To make several
# effects, use multiple tags.
#
# <user temp param: +x>
# <user temp param: -x>
# These do the same as <target temp param>, only for the user of the skill.
# Enter them the same as target temp param tags.
#
# <clear temp stats: user>
# <clear temp stats: target>
# Will clear the temporary boosts and falls of either the user or target,
# respectively.
#

What I can't figure out is how to make it end at the end of turn!

Now my idea so far is to use either <target temp param: +x> or <user temp param: +x> (depending on the nature of the skill) in the skill note box to buff the skill of the user, and to set the Speed to +100 to make it high priority with a message saying "{User} uses magic to defend!"  But I'm stumped with how to get it to deactivate at the end of the round.

My first thought was to have the skill call a common event that would make another skill be used that would play at the end of the round that targets the same target and has <user temp param: -x>, <user temp param: -x>, or <clear temp stats: user>/ <clear temp stats: target>.  The problem is if I have the call common event use the skill, it happens before the buff skill happens.  I can't figure out how to have the skill that cancels the buff be the LAST ACTION of the round.  Should be easy, just can't figure it out.

EDIT:  Just realized states can make this easier, as I can make a state last 1 round, but states only buff skills by %, not add/subtract an integer.  any ideas?