Guardian + Manifold Bond - [Guardian] completely refills your shield on depletion, resetting your shield gate. Killing enemies with 3 or more statuses reduces cooldown of [Guardian] by 5s, meaning every 6 kills on statused enemies resets Guardian's 30s cooldown, allowing you to essentially shield gate passively.

Negate - effectively gives status immunity, preventing dangerous toxin or heat procs at high levels and also preventing knockdown, particularly when run with Manifold Bond.

Reinforced Bond + Calculated Redirection - Boosts [Wyrm]'s shield to above 1200, making [Reinforced Bond] constantly active regardless of current shield level giving a +60% fire rate boost for free. [Calculated Redirection] is optional on frames that can make your sentinel immortal (eg Zephyr), as you can simply reload to hit >1200 then.

Mystic Bond - OPTIONAL mod that allows free ability casts after the sentinel uses abilities with cooldowns, which is accelerated through the use of Guardian + manifold or negate. This is only suggested on frames that don't require Brief Respite/Augur mods for shield gating as Mystic Bond will interfere. Works particularly well on Zephyr.

Momentous Bond - OPTIONAL mod that allows you to quickly revive sentinel after eximus kills.

Tenacious Bond - OPTIONAL mod that gives free flat 1.2x crit multiplier, requiring you to equip a sentinel weapon with >50% CC (Vulklok or Vulcax with Crit delay, or Prime Laser Rifle with Crit delay + CC riven).

Primed Animal Instinct - optional loot radar

[Seismic Bond] is used because a SURPRISING amount of abilities satisfy the condition to activate a free 30% efficiency, which shares a list with Arcane Intention: https://warframe.fandom.com/wiki/Arcane_Intention

[Crowd Dispersion] is OPTIONAL crowd control and can proc [Manifold Bond], but usually NOT recommend because it throws enemies away making it hard to actually shoot them.

[Sacrifice] is an optional mod that allows sentinel to revive you.