While we've seen ramp on camera a few times already, we haven't seen either of the UW decks (Monument or Gifts)
See you on the battlefield
I guess the logic of Undergrowth is that Red-mana creatures can use fire to burn through Undergrowth's effect and still deal damage through the thick foliage
My one bit of warning, this is not [casthaven]Leyline of the Void[/casthaven] and will not affect cards getting discarded or spells being countered
Heliods Intervention (Theros Beyond Death) White already has a lot of mass removal, but Heliods Intervention offers the ability to selectively sweep the board of enemy artifacts and enchantments while leaving your own untouched at instant speed
Its fragile, sure, and youre not going to be beating down anybodys door with this lil guy, but throw it into the mix with some other support and youve got one of the best black creatures in the game