Personally I don’t find Dovin weak. He was my best planeswalker in Inventor’s Fair even though my only lost match was with him. I think the core problem is that his abilities trick you into thinking that you have to use energize and overload cards but even the best of those cards don’t stand up to what is available from previous sets. Here’s just two examples within the same rarities that I used in Dovin when I shouldn’t have.
Deadlock Trap vs Prison Bonds
Deadlock Trap - colorless, rare, 3 mana, 3 shields. Energize 2 when cast, Overload 1, disable the first creature your opponent controls until the beginning of your next turn.
Prison Bonds - white, rare, 6 mana, 1 shield. Disable the first creature your opponent controls.
Prison Bonds is clearly better even though it is more easily removed unless reinforced. Trap is half the many cost with three times as many shields but requires you to make an energy match on each of your turns to get its effect, plus you need to keep generating energy in order to do so. Bonds just gets out there and does its job and your only goal then is avoiding setting the AI up to destroy it, plus it shuts down a certain creature with haste and hexproof that cost me lots of points this event. A way to improve Trap would be to make it eat one energy at the beginning of your turn and disable the opponents creature. This way you wouldn’t be stuck making off color matches just to trigger overload or even worse, not have any matches to trigger overload even though there is energy on the board. And I do appreciate the fact that Trap is colorless but it still would not be overpowered in non-white decks even with my suggested changes.
Era of Innovation vs Prism Array
Era of Innovation - blue, rare, 5 mana, 3 shields. When a creature type artificer or a support enters play, Energize 2, Overload 3, draw three cards.
Prism Array - blue, rare, 6 mana, 3 shields. When either player landfalls, disable the first creature your opponent controls until the beginning of your next turn and draw 3 cards.
Era of Innovation doesn’t even come close to Prism Array. In fact, Prism Array is essentially a combination of Era of Innovation and Deadlock Trap, that either you or the AI can activate for you. Sure you aren’t always guaranteed a landfall but you also aren’t always guaranteed an Overload 1, let alone an Overload 3. I know it’s been argued that Prism Array is OP and I can agree but that doesn’t make Era of Innovation any less bad than it is.
Sure Deadlock Trap plus Era of Innovation could be very strong in a heavy energize deck but that requires a lot of moving parts to come together. The alternative is to just run Prism Array. I suspect in Amonkhet (set after Aether Revolt), that is exactly what will happen because energy will become a useless relic of this games past.
Maybe I’ just ranting and maybe I’m just mad at myself for using the Kaladesh cards in Inventor’s Fair instead of the cards I should have used in the first place but I think it’s pretty obvious that you can accomplish the same things with non-Kaladesh cards while jumping through less hoops.
Side note, Dovin Baan’s third ability created support needs 5 shields like every other planeswalker’s third ability created support gets.