Udona, Hive-Minded Consumer

Eldrazi and Slivers you control are colorless Eldrazi Slivers in addition to their other colors and types.
Eldrazi Slivers you control gain all abilities of other Eldrazi Slivers you control. (For example, if an Eldrazi Sliver has devoid, each Eldrazi Sliver you control has devoid.)