Dylan, Feline of five moons

Vigilance, First Strike
Whenever you draw a card gain 1 life
When you cast a spell in your commander's
color identity add {w/u}{w/u} to your mana
pool if the spell's converted mana cost is less
than 4. If the spell's converted mana cost is
greater than 4 you gain X life where X is
equal to that spell's converted mana cost.