In this case, how many Characters with 5000 power or more am I considered to have when activating this [On Play] effect
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Adventurer's Airship Adventurer's Inn Aettir and Priwen Balamb Garden, Airborne Balamb Garden, SeeD Academy Baron, Airship Kingdom Blitzball Buster Sword Capital City Clive's Hideaway Cooking Campsite Crossroads Village Eden, Seat of the Sanctum Elixir Excalibur II Forest Genji Glove Gohn, Town of Ruin Gongaga, Reactor Town Guadosalam, Farplane Gateway Insomnia, Crown City Instant Ramen Iron Giant Ishgard, the Holy See Island Jidoor, Aristocratic Capital Lindblum, Industrial Regency Lion Heart Lunatic Pandora Magic Pot Magitek Scythe Midgar, City of Mako Monk's Fist Mountain Plains PuPu UFO Rabanastre, Royal City Relentless X-ATM092 Ring of the Lucii Sharlayan, Nation of Scholars Starting Town Summon: Bahamut Swamp The Gold Saucer The Masamune The Regalia Treno, Dark City Ultima Weapon Ultima, Origin of Oblivion Vector, Imperial Capital Wastes Windurst, Federation Center World Map Zanarkand, Ancient Metropolis

Umbris is a 1/1 Dimir creature for five mana that exiles cards from your opponents libraries whenever a horror or nightmare enters the battlefield
You can acquire trade tokens by completing missions or in Obtain Items by consuming cards with a rarity of three diamonds or higher