They are not overly common to see as typically Jace's draw cards and that ends games before ultimates tend to
Cards like Throne of Geth have seen play in Hardened Scales in Modern to spread +1/+1, -1/-1, and poison counters with proliferate
Its as if the designers tried to say: Hey, if youre bad at deck-building, heres at least some extra health for you. A good deck utilizes mana very accurately, and you almost never should end up with excess mana, unless something totally unexpected happens
Reactor Raid gives you value in the early game, the mid game, even the late game

Retreat: CCC Weakness: L Resistance: None ------------------------------------------------------------------------------ Goldeen A14 - Common Type: Water Evolution: Basic Pokemon Level: 12 HP: 40 W - Horn Attack (10) Retreat: None Weakness: L Resistance: None ------------------------------------------------------------------------------ Seaking A15 - Uncommon Type: Water Evolution: Stage 1 Evolution (Evolves from Goldeen) Level: 28 HP: 70 W - Horn Attack (10) WC - Waterfall (30) Retreat: C Weakness: L Resistance: None ------------------------------------------------------------------------------ Staryu A16 - Common Type: Water Evolution: Basic Pokemon Level: 15 HP: 40 W - Slap (20) Retreat: C Weakness: L Resistance: None ------------------------------------------------------------------------------ Magikarp A17 - Uncommon Type: Water Evolution: Basic Pokemon Level: 8 HP: 30 C - Tackle (10) W - Flail (10x) Effect: Does 10 damage times the number of damage counters on Magikarp

Check them out below: More details on Unfinity will be released soon and the set will have its own preview period that hasnt been announced yet