Everberg, 26, returns to North America after two seasons in Europe, including 50 games in the KHL in 2017-18.
Everberg has recorded 20 goals and 27 assists for 47 points in 66 career AHL games with San Antonio (2015-16) and Lake Erie (2014-15), along with three goals and nine assists in 70 NHL games with Colorado (2014-16).
Griffith, 25, tallied 15 goals and 26 assists for 41 points in 46 AHL games with Rochester last season, along with two goals and one assist in 21 NHL games with Buffalo.
An AHL All-Star in 2016, Griffith has 81 goals and 162 assists for 243 points in 249 AHL games with Rochester, Toronto and Providence.
Drafted by Boston in the fifth round in 2012, Griffith has totaled eight goals and 11 assists for 19 points in 79 NHL games with Boston, Toronto, Florida and Buffalo.
Schilling, 29, had a career year with Manitoba in 2017-18, posting six goals and 26 assists for 32 points with a plus-25 rating in 71 AHL games and representing the Moose in the 2018 AHL All-Star Classic.
Schilling has skated in 426 AHL games with Manitoba, Ontario, Rockford and Hershey, collecting 32 goals and 98 assists for 130 points.
Undrafted, Schilling has appeared in six career NHL games, all with Washington.