If I control a Selenia, Dark Angel and a Transcendence, when I use Selenia's Ability do I gain 4 life?
If I control a Selenia, Dark Angel and a Transcendence, when I use Selenia's Ability do I gain 4 life?
Yes, because cards do things.
because I'm thinking paying 2 life is part of a cost so its not the same as "losing life"?
Any time your life total goes down, it's considered losing life. That includes taking damage, paying life, or your life being set to a lower number (for example, by Biorythm).
Fluttershy is best pony.