Lucario

If you have lost a quarter of your starting life total or less, Lucario gains +3/+3 and first strike.

If you have lost half your starting life total or less, Lucario gains an additional +3/+3 and vigilance.

If you have lost three quarters of your starting life total or less, Lucario gains an additional +3/+3 and indestructible.
If you are at 1 life, Lucario gains life link.