Invisibility potions (balanced) and counter magic spells

We all love invisibility, but it is often done poorly, so couldn't we have something that actually makes you invisible, but reveals position upon action/attack/whatever but also gives you weakness if you are randomly hit and reveals your position, so it is not overpowered. Would be fun for pvp at some point. Unless invisibility already exists and I haven't discovered it yet.

I have still yet to see a game with counter magic/spells done well, counter magicians in parties would be an interesting class, as well as being fresh and original. A high consumption "silence" gem perhaps, some debuffs and buffs against magic, as well as hybrid weak attack/counter spells that reduce spell damage. Probably hard to implement but could be balanced against each individual spell. Maybe offensive spells would then need a counter resistance statistic.