Between Sliver Gravemother and Sliver Hivelord, both are acceptable commanders but I gotta give it to the Gravemother: encore is a powerful mechanic and even though the precon isn't really built around it outside of some discard or sacrifice slivers it's still a great way to get more value out of your deck, and the buildaround potential is huge
What you need is Reckless
Then if there are three or more collection counters on it, sacrifice it
He sure loves what he does
SE Secret Rare QCSE Quarter Century Secret Rare Angelica, Princess of Noble Arms X FIRE Level 5 [ WarriorSynchroEffect ] ATK 1200 DEF 2400 1 Tuner + 1+ non-Tuner monsters If this card is Special Summoned: You can add 1 "Horn of Olifant", or 1 card that mentions "Infernoble Knight Emperor Charles", from your Deck to your hand
You have those cards at the top of the heap that demand the most value, and then even among the rare SIR prints, a bottom rung of cards that although still hits, are much less in demand