Interaction Ive got some interaction slots here, with lands that can give a creature trample like Skarrg, the Rage Pits, to help a big Ape or Monkey punch through blockers
Summon: Leviathan: Leviathan is pretty bomby, especially if you make it semi-one sided with Sahagin or Ultros, Obnoxious Octopus
Sivitri has three abilities, and you can use them for your own protection, to tutor for dragon creatures, or to destroy all non-dragon creatures
Plus, you have the upside of creating 1/1 colorless Sliver tokens, which may not seem much, but these tokens receive all the benefits of other Sliver cards you have in play
The heavy emphasis on tokens and enchantments is fun too
It might be fine to only play with four or five sources of black mana in your deck