This piece of software lets you avoid damage in certain animations, which can come in pretty handy in PVP!
For example, in this clip I got hit with a two-handed weapon and received like only 30 damage, when in a normal situation I should receive 120...
Yes, it's fully legit. The only thing it does is handles when to suspend/resume the process.
For example, you miss a tackle and there is a guy trying to hit you with a 2-handed weapon...
You just hold down the Freeze Lag button for some time and you will receive minimal damage since you're still in animation because of the lag.