One bar magplar

croakie

Is Ritual or solar Barrage better for this build. I would think solar for the extra heavy damage but most builds have Ritual listed.

SugaComa

If you have oakensoul ring you're already getting the additional heavy attack but the 5% extra class damage is great if your using all class abilities ...

Ritual helps with health and dot cleansing

But what the Templar really needs is a change to radiant aura to be a back bar passive for the front bar like some of the other classes have, this will help greatly with sustain

Zodiarkslayer

Sweeps is usally enough for self healing. I would only slot Ritual if I already died a couple of times on a Boss.
And Ritual of Retribution isn't worth using anymore. It has less damage per tick than Unstable wall of Elements ticks. Not even talking of the explosion damage here.

The important thing is to slot an ability for Major Breach (ELE SUS or Razor Caltrops), Solar Barage, Radiant Glory and Puncturing Sweeps. That is the core of every SOLO Templar build no matter if you play One bar or Two Bar.

The last ability and the Ultimate are up to your own preference. On a one bar.