best elemental damage type for summoner templar?

[Pak0tac]

title ^
i thought maybe frost due to melee damage bonus to frozen enemies?

[Tenzek]

The question doesn't really have an answer. You should explain some details of your build, like what skills you're using and what you're trying to do. Maybe you can link your skill tree via the PoE site or Path of Building, which is a 3rd party program that you can find on the PoE official forums and that virtually everyone uses to help them design and share builds.

[Drake]

Since when is there melee damage bonus to frozen enemies ?
If you're summoner I would say don't use any elemental spells or attacks, just go full summoning.

[Slayer Slayerson]

all of the elements.
Go full summoner, get victario's chest armor and put hatred, anger and wrath on it.