Solarstaff Bright-Mage

Whenever a white permanent enters the battlefield, put a solar counter on Solarstaff Bright-Mage.
{w}{t}, Remove any number of solar counters from Solarstaff Bright-Mage: You gain life equal to twice the number of solar counters removed this way.
Whenever you gain 4 or more life, put a +1/+1 counter on Solarstaff Bright-Mage.