Removed from Play (All)

[Zyraen]

Following from Glossary, this is NOT a house rule.

Removed From Play

The creature can’t take actions.
The creature has neither line of sight nor line of effect to anything, and nothing has line of sight or line of effect to it.

An effect that removes a creature from play specifies where the creature reappears when it returns to play. Typically the creature reappears in the space it left, or in the nearest unoccupied space if that space is now occupied.
A creature is normally subjected to this condition because it has been transported to another plane of existence or is engulfed or swallowed. Whatever the cause, the creature’s turns start and end as normal.

[Zyraen]

Hence, unless otherwise stated, a Character that is removed from play cannot take actions.
Not having LOS / LOE to "anything" would presumably mean it has no LOS / LOE to itself, as well.

This means no Second Wind, no Total Defence, no Heal Check to end a Save Ends condition.
Likewise, those who are Removed from Play cannot Delay their Turn, and may effectively Miss a Turn while Removed from Play.

Because some effects are written as Removed from Play (Save Ends), logically speaking, this means that you can make Saving Throws as normal at the End of your Turn.

Hope this helps.