Fynn doesn't have to still be on the battlefield when someone (preferably an opponent) gets their tenth poison counter.
It is kind of interesting that you get to target your creature (for the purpose of Silverfur Partisan?), but this is just so much harder to use than something like Dromokas Command, for instance
Iconic Cards: Splinter Twin, Senseis Divining Top, Copy Cat, Living End, Primeval Titan, Grinding Station Popular Decks: Oops, All Spells!, Twin, Grinding Station, Mill, Belcher, Storm 6 Ramp Ramp decks want to generate a ton of mana to cast really powerful cards
As long as a card has applied the day/night cycle in the current game, you need to do the following check as soon as the next turn starts: If its Day: If the last turns player didnt play any spells, it becomes night
Tip: Cards care about exact matches, Goblin Matron fetches a Goblin but not a Shaman