10 cards where the text includes “amass” and (the card is available on Paper) and the set is “ltr” and the rarity is equal to common

Deceive the Messenger (The Lord of the Rings: Tales of Middle-earth #47)
Dunland Crebain (The Lord of the Rings: Tales of Middle-earth #82)
Easterling Vanguard (The Lord of the Rings: Tales of Middle-earth #83)
Mordor Muster (The Lord of the Rings: Tales of Middle-earth #96)
Orcish Medicine (The Lord of the Rings: Tales of Middle-earth #104)
Surrounded by Orcs (The Lord of the Rings: Tales of Middle-earth #73)
Swarming of Moria (The Lord of the Rings: Tales of Middle-earth #150)
The Torment of Gollum (The Lord of the Rings: Tales of Middle-earth #110)
Treason of Isengard (The Lord of the Rings: Tales of Middle-earth #74)
Warbeast of Gorgoroth (The Lord of the Rings: Tales of Middle-earth #152)

This search is finished. Now the real work can begin.