I also like it in Type Four which often has elevated casting costs to bring back due to the infinite mana nature of the format, and bringing back a giant 10/10 and gaining 8 life in one card is pretty strong there
Mill decks will definitely be including this Jace Variant, as its ultimate ability is too tempting and hilariously mean to resist, and counter manipulation via Proliferate makes it that much easier to activate
Further to this he provides a wall near impossible to attack into and then a threat that is near impossible to race
However, this might also affect lesser-seen decks, giving them a bit of a needed buff
For a considerable 7 mana, Balamb Garden can transform into Balamb Garden, Airborne, a legendary artifact
Niko Aris can make more Shard tokens to continue building up card advantage, especially in the late game