Summary: Panzer is hands down the best Steel Path pet. It is immortal, and it has quills for viral priming too. I use Link Health and Primed apack Leader for base Survivability. I then use [Bite]'s critical chance for the [Tenacious Bond]; it provides a bonus 1.2 Final Damage multiplier to your weapons. [Tandem Bond] increases beast damage on melee heavy attacks and increases your combo passively. Also, [Tandem Bond] is a flexible bond; you could use [Reinforced Bond], [Seismic Bond] if you have Gloom or another channeled ability, [Mystic Bond] if you don't rely on shield gating, [Vicious Bond], Sharpened Claw, [Tek Assault], Synth Mods, etc. [Hunter Recovery] is there to heal you or you fan use [Martyr Symbiosis] instead, or whatever you enjoy. Finally, [Primed Animal Instinct] is equipped for loot radar, and [Fetch] is equipped for the QOL.

Note: [Bite], [Tandem Bond], and [Momentous Bond] will allow your Panzer to clear any normal Star Chart mission due to the very high damage. In SP, Panzer falls off in damage, but it still provides a decent amount if you use a 100% armor strip. We mostly use the bonds to enhance our own damage and to have a good melee weapon ready and primed at all times.

Disclaimer: Change Link Health to Shields if needed. I didn't use [Martyr Symbiosis] since almost every warframe is immortal if built correctly and played well. Also, I have Unairu waybound passives unlocked for self-revives too, making [Martyr Symbiosis] too redundant for me to equip. If you very much need it, then use it instead of [Tandem Bond], or if you really like Tandem, then over [Momentous Bond].

Enjoy ;)