When combing the Synthesist and the Eidolon mulitple issues when using the Temp Bonus - please have one Temp Bonus that adds all fields to the Synthesist
1. the synthesist uses the eidolon’s Strength, Dexterity, and Constitution, but retains his own Intelligence, Wisdom, and Charisma,
2. synthesist gains the eidolon’s hit points as temporary hit points.
3. synthesist is still limited to the eidolon’s maximum number of natural attacks.
4. Shielded Meld (Ex): At 4th level, fused with his eidolon, he gains a +2 shield bonus to his Armor Class and a +2 circumstance bonus on his saving throws.
Greater Shielded Meld (Ex): At 12th level, whenever the synthesist is fused with his eidolon, he gains a +4 shield bonus to his Armor Class and a +4 circumstance bonus on his saving throws.
5. If the synthesis's eidolon has the Skilled evolution, the Synthesist gains the bonus to that skill.
6. A synthesist can use aspect to increase his own natural armor. However, when fused, he gains the eidolon's natural armor bonus, so this doesn't stack with his own natural armor bonus.
The eidolon has no skills or feats of its own.
7. When fused, use the eidolon's BAB instead of the summoner's class BAB
8. So a synthesist using his eidolon-suit's natural weapons is proficient with them.
9. If the synthesist's eidolon has the Skilled evolution, the synthesist gains the bonus to that skill.
While fused with his eidolon, the synthesist can use all of his own abilities and gear, except for his armor