With the ban of Unaware and subsequent collapse of stall, the meta of Inheritance has definitely swung to favor offense and HO teams. That doesn't mean defensive mons as a whole are dead, however; here are some solid defensive options I've been playing around with.
Toxapex @ Black Sludge
Regenerator
252 HP/252 Def/4 SpD; Bold Nature
-Scald/
Body Press
-Toxic/
Body Press
-
Slack Off
-
Teleport
Easily the best defensive mon, Toxapex's great bulk allows it to be just as annoying as it always is. Pex is one of the few mons that often keeps to its cannon set, however it can also inherit from Slowbro to acquire
RegenPort, making it even more annoying while giving pivot support (valuable in any offensive meta). Scald and Toxic are standard damage dealers for this set, although Bro specifically gives access to Body Press off 443 Def (usually going phys Def anyways) if one wants more offensive pressure, or possible Screens on HO.
Aegislash @ Rocky Helmet/Leftovers/Colbur Berry
or Doublade @ Eviolite
Water Absorb/Cursed Body
252 HP/4 Def/252 SpD; Calm Nature
-
Recover/
Strength Sap
-
Night Shade
-Toxic/
Will-o-wisp
-
Taunt
Aegislash and Doublade possess a unique niche as two of the only defensive mons that resist both STAB of Lycanroc-D! Terrakion, pretty much blanking any Terrak without Crunch (which it often drops for Psychic Fangs against Pex); SpD investment can also let them take on Comfey inheritors. Their best donor is probably Jellicent, which provides them with recovery, consistent damage and Taunt, as well as extra defensive utility with Water immunity or disabling Choiced mons. Doublade is physically bulkier thanks to Eviolite, while Aegislash has the freedom to run multiple items like Helmet for extra chip, Leftovers for passive healing or possibly Colbur Berry to tank a Knock Off.
Swampert @ Leftovers
Sap Sipper
252 HP/4 Def/252 SpD; Careful Nature
-Stealth Rock
-Earthquake
-Toxic/Ice Punch
-
Milk Drink
or
-
Defog
-Earthquake
-
Glare
-
Roost
There is an obvious appeal in removing a 4x weakness, and there happen to be two defensive Sap Sipper donors that give Swampert good utility; with this weakness eliminated, Pert's defensive capabilities really shine, with max special bulk even letting it tank hits from Sheer Force inheritors (
this thing once single-handedly saved me against !Nidoking Kyurem, which wasn't quite strong enough to 2HKO). !Miltank packs recovery while still allowing Pert to perform as a Rock setter, with either Toxic to weaken bulkier opponents or Ice Punch to hit Grass and Flying types. !Drampa Swampert instead takes the role of a Defogger that resists Rocks, and does provide one distinct advantage over Miltank with
Glare to hamper fast offensive threats.
Ferrothorn @ Leftovers
Flash Fire
252 HP/4 Def/252 SpD; Careful/Sassy Nature
-Spikes
-
Rapid Spin
-
Will-o-wisp
-Iron Head/Gyro Ball
The other big winner in removing a 4x weakness, Ferrothorn gains dual hazard utility with Rapid Spin as well as Wisp to cripple physical attackers; nature depends on which Steel STAB you want, bigger hit vs more PP and consistent damage. The main issue is that Ferro is much more reliant on Leftovers compared to normal since you lack recovery outside of Rest.
Shuckle @ Smooth Rock
Sand Stream
248 HP/8 Def/252 SpD; Calm Nature
-Stealth Rock
-Toxic
-
Whirlwind
-
Slack Off
Inheriting Sand Stream from Hippopotas grants Shuckle a huge boost to its special bulk, making it a great setter for Sand teams. Having faced Sand teams multiple times from 1300+ players, I admit they can be scary to deal with, with threats like Sand Rush Ttar (!Sandslash) and Xurkitree (!Dracozolt), and probably would be screwed if I didn't naturally lean towards balance offense with my building. Shuckle enables these teams well with Rocks and Toxic, Slack Off for sustain and Whirlwind to provide mid-game utility against the many set-up sweepers in the meta. As bulky as it is, Shuckle is extremely weak to Taunt, and the need to keep Sand going as long as possible means it doesn't have the luxury of Boots, so removal is essential to keep it healthy.
Whatever
Natural Cure
252 HP/4 Def/252 SpD; Calm Nature
or 252 HP/252 Def/4 SpD; Bold Nature
-
Rapid Spin
-
Scald/Toxic
-
Recover
-
Teleport/Flip Turn
And now for a defensive donor, Staryu is one I haven't seen a lot of conversation about; in no uncertain terms, Staryu is easily one of
THE best defensive donors in the entire Meta. Staryu has a ton of great defensive assets it doesn't get to show off normally;
hazard support, status in Scald or possible Toxic, instant recovery, absorbing status with Natural Cure and pivoting. Spin inherently has an edge over Defog in a fast-paced meta like this, so giving any defensive mon that ability to Spin is great. Nat Cure and Recover can make it hard to wear down any good !Staryu inheritor, and Teleport allows you to safely get in your ally (Flip Turn is also an option if you're scared of Taunt). This set is very splashable in terms of inheritors, with multiple great options like Fini, Pex, Pert, pretty much any defensive mon;
I've actually run this set on Aegislash, and even that put in a ton of work. If your inheritor packs solid SpA, you can even utilize options like Future Sight (Starmie) or Ice Beam.
Thanks to its movepool, Starmie can also be a good offensive donor, between Hydro, Flip Turn, BoltBeam, Meteor Beam (Starmie), Flash Cannon (option for Steels) and Trick, as well as either Cure or Analytic to further boost power. Bottom line,
Staryu/Starmie is possibly the most slept on donor in the meta.
This is only the tip of the iceberg in terms of defensive options for the tier, but I feel these are a good place to start for anyone new that wants a defensive option for their team.