The effect of Blossombind's last ability doesn't remove counters that are already on the enchanted creature.

Damage from a source with wither or infect has no effect on a creature enchanted with Blossombind. No -1/-1 counters are put on it, and no damage is marked on it. The damage is still dealt for purposes of effects that care about damage, such as lifelink.

If a replacement effect allows a player to modify or replace an event by untapping or putting counters on a creature enchanted with Blossombind, that player may apply that replacement effect, but they won't get counters. If the original event is entirely replaced, the original event won't happen.

If the cost of an ability or an additional cost of a spell requires untapping or putting counters on a creature enchanted with Blossombind, that cost can't be paid. If a resolving spell or ability says that a player may untap or put counters on that creature, that player can't choose to do so.