mtg card value over time What Are the Most Valuable Cards in Magic: The Gathering? Found a page of MTG

Seymour Flux Rarity: Rare TYPE: Legendary Creature SUBTYPE: Spirit Avatar CMC: 5 Mana cost: USD: $0.29 EUR: 0.38 TIX: 0.30 EDHREC RANK: 12885 (5/5) At the beginning of your upkeep, you may pay 1 life

But the cost of gifting an extra turn is absurd

However, if you do and the target is illegal as the ability tries to resolve, it won't resolve and none of its effects will happen

Vincent Valentine / Galian Beast Though it starts tiny, Vincent Valentine can be devastating when you combine it with removal spells like Sephiroth's Intervention

theyre easy to learn and play with, but are very unlikely to be competitive if played against decks which have been specifically built with powerful combos and strategies in mind

Id say that its an above-average set for the world of Cube, and thats even accounting for my assessment of its batch of battles as being relatively weak