Explanation for Shield Gating
Shield gating is a very important aspect of surviving consistantly at higher levels of content in Warframe. While health "tanking" will get most players through several hundreds of levels of content but shield gating will take any player into the thousands

But besides this and what I feel is most important is that shield gating takes up less space on already crammed for space builds. Brief Respite takes up only one mod slot and is an Aura mod while health tanking can take up 2-3 spaces in the regular mod section.

Do what you must but this build is for people who want high tier survivability on [Lavos] which might not be you and thats fine.

Gameplay
The gameplay for this build is very particular because [Lavos] cannot generate shields by casting abilities, [Lavos] needs Condemn to crowd control and generate shields and casting abilities out of order in a tense scenario could make you die.

In order when approaching a crowd of enemies -

1) Cast Condemn to crowd control the enemies and give you shields to [Protect] yourself from other enemies
2) Cast Transmutaion Orb to instantly get back Condemn for approaching enemies
3) Cast Ophidian [Bite] (on at least 4 enemies) to get back Transmutation Orb to have ready
4) Prime with a heat inherit primer (link for that)
5) Cast Catalyze
6) Repeat

I know that this can seem like a lot but this whole rotation takes about 5-8 seconds

Also of course you can use the abilites in any order you want in different circumstances but the order I laied out IS the most efficient to survive and cast your abilites with practically no cool down.

Modding
[Natural Talent] is 100% needed to survivewith this build, but if have two archon shards for casting speed then replace it with [Archon Vitality] (not for the health but for the double heat procs for Catalyze).

Arcanes
I do not have Arcane Barrier so I can not speak for its usefulness here but I tried Arcane Aegis and it didnt work wonderfully so I did not include it in this final build. Some people use Barrier and Aegis at the same time.
Molt Efficiency is used to counteract the negative duration with this build, you can replace it with Molt Augmented if you want. Arcane Eruption is free Crowd.