Rito plz consider this as the thresh buff. (would love to get one of them red comments)
The relic shield changes are going to be off putting and might give him a lower win rate and pick rate than usual but if he needs a minor buff consider a buff to base armor ,maybe just a small increase to 30-32.
I would really hate to see the small buff end up being too large and him getting nerfs elsewhere.
If he is weak for a patch or two while you monitor him after a small buff i'm fine just plz don't over do it.