Im a little less sold on the Investigators, whose two abilities both seems generally useful but not terribly focused here
The power of Lurrus comes from always having access to it via the Companion mechanic
Poliwag (Promo-A 103 / P-A) card How to get: Was obtained randomly through Promo Cards gifted after securing victories in solo battles during the Zoroark Drop event running until September 13, 2025
If you plan to play with them in sleeves, yes, you should seal altered proxies
But it's here at the six spot since it's playable in Commander only
Sengir, the Dark Baron's third ability will trigger no matter how the player lost the game: due to a state-based action (having 0 or less life, trying to draw a card from an empty library, having 10 or more poison counters), because of a spell or effect that states they lose the game, because your awesome might has left them with no choice other than concession, or for any other reason