Double Sylph Attack type

[chipsig]

Hi i have a short question.
If i have a duel sylph which type of attack should i train?

a short example:
1 have an Odin.
Should i train Matk and patk? or only one of this? And which attack type does damage for a skill?
Former, a hecate uses patk and a venus matk. If i use a skill like "endless engulf" with odin, but i have all equipment parts with + 1500 matk refined and only matk divinity souls, so my matk is much more higher.
Calculate the system for "endless engulf" with matk or patk?
And what happends with skills where you cant know, which attack type it could be, like "apocalypse judgment"?

At the end my final question: Is it more effective to only train one type of attack, because the it uses always the highest amount or should i train it in the same way so all are a little bit lower, but there is no difference in the skills?

thanks in advanced

[jamidc1992]

Odin skills deal MATK and PATK at the same time. Train both.

Thor skills are MATK if Electro, PATK if Fire. Train both or only one if you only use one.

Frigga skills are all MATK (even the Wind skills). Train MATK.