mtg all sliver cards Spectral [Premium Deck Series: Slivers] All Sliver creatures get +1/+1. SLIVER Legion Commander Deck Slivers

Im not sure about Doom Whisperer

As long as you aren't running a Stax deck that is actively limiting your opponents from casting multiple spells per turn with cards like Winter Orb I think you'll get enough value out of Mangara to justify its slot

Christopher Robin Hunny Sage is a Must-Have For All Winnie The Pooh Decks Stepping into the magical realm as a dream for fans of the Hundred Acre Wood, Christopher Robin - Hunny Sage acts as the definitive engine card for the new Hunny tribal archetype

Ive not yet cast Travel Through Caradhras so Im very curious to see how it plays

One card that comes to mind for fixing your library is Insatiable Avarice

If these are a little beyond your budget, you may be able to actually afford some expensive basics, perhaps