Irina, Knight's Seraph

{t}:Regenerate target Knight You Control.
{r}{w}:Regenerate Irina, Knight's Seraph.
Irina, Knight's Seraph's power is equal to the number of Knights you control and toughness is equal to X amount of mana spent to cast Irina, Knight's Seraph.
At the beginning of each end step, if two or more Knights died under your control this turn transform Irina, Knight's Seraph.