Solemnity

Players can't get counters.
Counters can't be put on artifacts, creatures, enchantments, or lands.

Leonardo, Sewer Samurai

Sneak {2}{W}{W}
Double strike
During your turn, you may cast creature spells with power or toughness 1 or less from your graveyard. If you cast a spell this way, that creature enters with a finality counter on it. (If a creature with a finality counter on it would die, exile it instead.)

Scholar of New Horizons

This creature enters with a +1/+1 counter on it.
{T}, Remove a counter from a permanent you control: Search your library for a Plains card and reveal it. If an opponent controls more lands than you, you may put that card onto the battlefield tapped. If you don't put the card onto the battlefield, put it into your hand. Then shuffle.

Vigilant Martyr

Sacrifice this creature: Regenerate target creature.
{W}{W}, {T}, Sacrifice this creature: Counter target spell that targets an enchantment.