Nira, Hellkite Duelist

Flying

: Search your library for a Dragon permanent card and put it into your graveyard. If you do, Scion of the Ur-Dragon becomes a copy of that card until end of turn. Then shuffle.

Flying, first strike, trample, lifelink, haste

At the beginning of combat on your turn, other Spiders you control gain flying, first strike, trample, lifelink, and haste until end of turn.

Flying

When Niv-Mizzet enters, reveal the top ten cards of your library. For each color pair, choose a card that's exactly those colors from among them. Put the chosen cards into your hand and the rest on the bottom of your library in a random order.

If you would lose unspent mana, that mana becomes black instead.

At the beginning of your first main phase, look at the top card of your library. You may reveal that card if it has three or more colored mana symbols in its mana cost. If you do, add three mana in any combination of its colors and put it into your hand. If you don't reveal it, put it into your hand.

Sliver cards in your hand have warp .

Sliver creatures you control have "When this creature enters, conjure a random card from the Slivers Spellbook into the top ten cards of your library at random, then draw a card."

Warp

Flying, menace, haste

Whenever this creature attacks, draw two cards.