I've tried searching for the answer in the "One Synthesist Thread to rule them all" but either I missed it or maybe I just need a clear cut answer rules wise.
If you multi-class a synthesist, what happens?
Does multi-class work normally such that the synthesist, uses its summoner level and adds its bab, saves and abilities, then adds the bab, saves and abilities of another class.
For example, Level 2 Paladin and Synthesist 2 Quadruped with charisma 16..
For the synthesist, you gain
+2 bab, +3 Fort,+ 3 Ref, Evasion
For Paladin
+2 bab, +3 Fort, +3 Will, Divine Grace and lay of hands
Will this make the synthesis/paladin have
+4 bab, +9 Fort (3 from synthesis, 3 from paladin, 3 from divine grace), +6 Ref, +9 Will, Evasion, Divine Grace and Lay of hands?
Or will multiclassing not work and leave the synthesis/paladin when fused to have just the bab and saves from the eidolon?