With the addition of settlers of kalgur in 3.25, there was large meta sweeping changes, to meele and defense, some builds were made unviable as well. The two ascendancies I do not recommend league starting are Occultist and Assassin. Assassin has it place with sanctum or bosses however. Occultist offer good AOE and damage but its defense can be lacking, I think this league offers stronger league starters elsewhere. Slayer is likely to be overall the best defensive and offensive value with the endurance charge changes. Warden damage potential is likely to be extremely high, if you can solve for defense thene Warden is a great choice. Champion got nerfed very hard and is likely not going to be a top ascendancy anymore

My Top 3 Ascendancies for 3.25
1. Slayer
2. Hierophant
3. Trickster

Viable league starters list
1. Archmage Hierophant (Ball Lightning / Frost bolt Etc
2. Hexblast Inquistor/trickster
3.Bleed Gladiator (Lacerate Earthquake Dual Strike etc Bleed Bow)
4. Lightning Strike/ Ele strike/ Ele Bow Warden
5. Aura Stacking Champ Lightning Strike
6. Poisonous Concotion of Bouncing Pathfinder
7. Frostblade Trickster
8. Any strike skill slayer
9. Slam/Strike Berserker
10. Necro holy relic
11. Deadeye/Warden bow builds (LA, EH, Ice Shot)
12. Molten Strike Str stacking Jugg
13. Str stacking wander (Yes you can league start this but only if youre experienced)
14. Locus Mine Trickster