End of abilities given off by creatures
"Give off abilities" is not clear. It helps if you use proper jargon or at least an example. I believe you are talking about continuous effects created by static abilities such as Wizened Cenn's.

Effects created by static abilities take effect the moment the object on which they reside enters the battlefield, and they end the moment that object leaves the battlefield.

For example, say you have Wizened Cenn and Amrou Seekers on the battlefield, and your opponent deals 2 damage to each of your creature. This marks two damage on both your creatures. This kills off your Cenn, which reverts your Seekers to 2/2, which kills them off too.