Effects that modify a creature’s power and/or toughness without setting them to specific values will apply to the creature no matter when those effects began. The same is true for counters that change the creature’s power and/or toughness.

Ovinize overwrites all previous effects that set the creature’s base power and toughness to specific values. Any power- or toughness-setting effects that start to apply after Ovinize resolves will overwrite this effect.

If the affected creature gains an ability after Ovinize resolves, it will keep that ability.