At level 42, take either Cauterize, Eye of the Tiger, Spine of the World, or Pain Enhancement System. I don't think anything else is a good choice.
I only recently discovered how powerful the arcane amplification drone prodigy can be for PM. IMHO, the braid system of timeline threading is one of the most powerful PM mechanism, and combined with the AAD, it can deal insane damage.
Assume you have a powerful foe.
1/ create an AAD between you and him.
2/ cast rethread to braid your AAD and the foe
3/ cast a beam that will damage the AAD and your foe. Assume you spell deals 1000 damage and that the braid redistributes 50% of the damage.
Your foe will take:
- 1000 damage from the beam
- 1000*160%=1600 arcane damage from the AAD
- 1000*50% = 500 braided (irresistible) damage
Hence ~3k damage vs 1k normally.
Note that if there is another braided foe in the vicinity he will take 1600 damage from the AAD and will rebraid 800 out of it (reduced by his arcane resistance) to the initial foe (plus another eventual normal braided damage from the beam).
The AAD has 0% resistance and *all* damage it take from your spell is rebraided, which makes the braid mechanism extremely powerful when used with it.
More, the AAD is also extremely powerful in terms of defence and can, for instance, completely block access to a corridor to protect you. This saved my life a couple of time.
Only drawback. The amplified arcane damage can hit you. Be careful to be at at least 5 tiles from the AAD.