The question is how to make sure that someone else suffers the damage and you are properly placed the benefit - without standing so far back that the ablative armour people in front are all destroyed.
My personal view is to ask:
Has the other person lasted a while - yes
Have they annoyed a lot of your equivalents / betters and survived - yes
Are they going to fall hard if at all - damned straight
Do you want to pick an unnecessary fight / fight unprepared - not if you want to live
Basically an immortal powerful evil will probably:
1. Remove / hide / destroy weapons that can hurt them
2. Subvert enemies that could be dangerous / turn them against each other
3. Use strength sparingly and indirectly to avoid it being fully measured
4. Leave traps and misdirection along any path that might lead to their destruction (the RW is vulnerable to swords forged in lava - to Kal Saitharak!)
5. Use time as the keenest weapon of all
Consider a certain Elenien big bad that's making hay while the sun shines and the north is silent...
That said none of the gods want competition or Azrai back, nor do the ancient awnies want a reborn master, etc - the flower that stands too tall merely collects enemies and falls...