the real advantage of Sev is against spot removal heavy decks, where you gain massive card advantage from it. it’s not usually a card you want against aggro or proactive midrange, but against decks that win by removing and out valuing, it’s immense comeback power
some other fun non-white sev targets (including some good recommission targets too):
WAR Narset
Standstill
Hall of Storm Giants
Tome of the Infinite
Sedgemoor Witch
LOTV
Recurring Nightmare
Mire’s Grasp
Laelia
Seasoned Pyromancer
Fable of the Mirror Breaker
Tireless Tracker
Celestial Colonnade...
Mythos of Illuna is decent in midrange/WOTC-cube land where you can copy ANYTHING, even a Field or a walker, and sometimes also blow something up with the fight rider
IF your cube cares about artifacts, prowess, or graveyards (spoiler: your cube cares about graveyards), paying ZERO mana to draw a card, cast a spell, and put an artifact into your graveyard is kinda broken and i’m not passing them to you, sorry
i’ve played it, it is quite nice, just ended up a little too slow for me. i’m also a wish fanatic, and having larger draft pools makes the “good” wishes (the ones that cost 2 mana) much better, because you’re more likely to have relevant stuff in there