Temple Shisa unique effect question

Should this be read so that when a Shisa activates, both lose 1 or 2 activation counters (depend win on action taken), in essence meaning the two have a shared activation pool? Or is it only in certain circumstances that both lose an activation counter?

 

I think it should mean that they have a shared pool.
One activates, both lose one/two.
One uses Vitality both gain one.
Was about to say one is attacked in melee both lose one but as try are tireless that doesn't happen.

By Mcgreag

Thanks! Just wanted to make sure I use them correctly.

By dank --

Dan Stieper Karbing

yenohoney