Build help and opinions (new player)

I am only SHD level 99 so bare with me if this build is cancerous to the eyes, i know it needs work to say the least. This is what I've come up with so far and as you all know this game is grindy so its been difficult to find better gear, I have been doing targeted loot activities (summit and countdown) and playing everything on challenging. Most everything i have I have already swapped out at least one attribute. This brings me to my questions, first off is countdown going to be my best for loot grind? and secondly what are some things that look good so far and just require some upgrading and what are things i just need to swap out entirely.

I am currently looking to swap out my chest for a ceska w/ obliterate but have not found that yet. I also know the better roll on St. Elmos would be Dmg to TOC but again haven't found that yet. Besides that i am all ears and appreciate all the help given.

https://preview.redd.it/vbd859pyxp2d1.png?width=1110&format=png&auto=webp&s=9c570e136ad587b68fd0f08f4b75cb1b72a3f4cd

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