Helga, Skittish Seer

Whenever you cast a creature spell with mana value 4 or greater, you draw a card, gain 1 life, and put a +1/+1 counter on Helga.
{T}: Add X mana of any one color, where X is Helga's power. Spend this mana only to cast creature spells with mana value 4 or greater or creature spells with {X} in their mana costs.

Vivi Ornitier

{0}: Add X mana in any combination of {U} and/or {R}, where X is Vivi Ornitier's power. Activate only during your turn and only once each turn.
Whenever you cast a noncreature spell, put a +1/+1 counter on Vivi Ornitier and it deals 1 damage to each opponent.

Kefka, Ruler of Ruin

Flying
Whenever an opponent loses life during your turn, you draw that many cards.

Kefka, Court Mage

Whenever Kefka enters or attacks, each player discards a card. Then you draw a card for each card type among cards discarded this way.
{8}: Each opponent sacrifices a permanent of their choice. Transform Kefka. Activate only as a sorcery.