How to do shields right
Shields in games have historically been used by tanks/healers/defensive character builds. The reason for this, is that most top tier abilites for characters able to utilize a shield scale a lot better on two-handers/dual wielding instead of offensive shield abilites.
As a result, while you can use a shield as an offensive dps character, it is usually better to use other combinations instead.
In my opinion, this unnecessarily limits the potential variation in character builds. It also ruins the game for people who love using shields but also love to be offensive.
Shields have been used offensivly in real life. We have many examples for this, ranging from gladiators, some roman legions and duelists. If we take a modern example, a spear user will almost certanly decimate any sword user of any skill. But, give a shield to the sword user, and this gives the sword user tons of offensive potential, even tipping the odds in favor of the sword and shield user. (Watch sword/spear masters on youtube duel in real life to learn about why).
What should be done instead, is allow your character to be built in such a way that you can play with a shield offensivly if you want. Obiously, a two-handed user would have more raw power, a dual wielder would have more speed, but the shield user would have his own pros and cons.
My dream is to play an offensive shield using fighter/x combination. The strenghts of this kind of character build should be a combination of utlity, control and flexibility. Lacking the raw damage a 2H/Dual wield build has but compensating in defence and utility. It should obiously not be as tanky as a dedicated defensive tank build. A balance between offense and defence. It should be a middleground.
For this to work, there needs to be offensive abilites that are balanced and viable in comparison to the 2H/dual wield abilites. For this to be balanced, you would need to sacrifize the massive defence a tank has and the high damage of 2H/dual builds.
Some strenghts a build like this could have:
High counterattack damage (After you block/deflect a spell, deal more damage)
More control than a pure damage dealer (More slows/spell interupting potential)
More defensive capabilities than a 2H/Dual wield character (Extra defensive cooldowns/passives)
More tactical cooldowns (Instead of flat % dmg increases, have immune to slows, stund etc, reflect spells, reflect damage)
Some weaknesses a build like this could have
Less DPS potential than a 2H/dual wield build (Simply less damage)
Less Defensive potential than a tank (Simply less health/armor)
Less DPS cooldowns than a 2H/dual wield (No pure DPS cooldowns)
Less Defensive cooldowns than a tank (No immortality cds, or reduce damage taken by 70% cds for example)
Less utility than a tank (Less auras/supporting abilites for other teammates)