Tatsunari, Toad Rider (123)

Whenever you cast an enchantment spell, if you don't control a creature named Keimi, create Keimi, a legendary 3/3 black and green Frog creature token with "Whenever you cast an enchantment spell, each opponent loses 1 life and you gain 1 life."
: Tatsunari and target Frog you control can't be blocked this turn except by creatures with flying or reach.