At 2 mana, Red instead of black and the ability to recur the same spell multiple times, it seems more playable than Yawg will in a number of decks and, of course, it’s unrestricted. However, it seems notably weaker against GY hate than Will as you need a much larger GY to do really broken things. How many Time Walks does one need to cast though?
The Sun Titan / Muldrotha synergy seems to be the route that would be most broken as you can keep it around for a while, and get it off an Oath or Dread Return. Get back some Black Loti + Time Walks to finish the game.
A “hate” card by definition is only supposed to be good against a subset of decks, and bad against the others. The problem is that Vintage doesn’t contain the full spectrum of decks available to it. Every deck has become some Control + Combo hybrid, or Control + Aggro hybrid. Pure combo decks get destroyed by the restricted list. Pure Aggro is not fast enough. Pure control doesn’t finish decks off fast enough either. These weird hybrid decks cause all sorts of fundamental issues of almost every deck bwing affected by what should be narrow “hate” cards.
Willingness to errata cards makes Hearthstone a much more enjoyable game to play. They probably though they were doing good pushing the power level of Planeswalkers there and ended up having to ban/restrict a bunch of them. But if they could make slight adjustments to the text and mana cost these cards would be fine.
My point was more that thw 3x FKZ is probably better split into other DR finishers as well as the 2x Titan. There are a plethora of other good options, e.g. Kologhan, Laboratory Maniac, Muldrotha, Griselbrand, Hatebound Flayer. This allows the deck to overcome scenarios where you can’t win with Bridge into a bunch of zombies.