Flying

Cumulative upkeep—Gain control of a land you don’t control. (At the beginning of your upkeep, put an age counter on this permanent, then sacrifice it unless you pay its upkeep cost for each age counter on it.)

Herald of Leshrac gets +1/+1 for each land you control but don’t own.

When Herald of Leshrac leaves the battlefield, each player gains control of each land they own that you control.

Enchant creature

Enchanted creature has swampwalk. (It can’t be blocked as long as defending player controls a Swamp.)

Whenever an opponent casts a green spell, you may pay {B}{B}. If you do, look at that player’s hand and choose a card from it. The player discards that card.

{B}{B}: Return Leshrac’s Sigil to its owner’s hand.

Protection from black

At the beginning of your upkeep, Minion of Leshrac deals 5 damage to you unless you sacrifice a creature other than Minion of Leshrac. If Minion of Leshrac deals damage to you this way, tap it.

{T}: Destroy target creature or land.