[Gestalt][Dm Seeking Aid] Idea's on how to challenge my party a bit more.

[Dreamtime]

If your dealing with the ressurection of serpentine god in your game, exit this thread immediately!

The party:
-Barbarian/monk - The tank
-Barbarian/Fighter - The BBSF
-Slayer/Inquisitor - The archer
-Investigator/Oracle - Sneaky support

-Homebrew world based heavely on chaos, destruction and an upcomming apocalypse.
-Its still a heavy roleplay game due to all players being quite competent at roleplaying out situations and doing investigative work.
-Party just hit lvl 7.
-Unchained bonus progression.(Made me worry less about WBL)
-Alignment: good/evil/neutral still exist but chaotic/lawfull got dumped.

I've noticed that challenging the later 3 is quite manageable but the first one is a little bit of a problemcase due to archetype combinations. To challenge him, i'm essentially condeming the others to death if they'd get targetted and i've ran out of ideas how to challenge him without instagibbing the other 3.

Lately they've just been steamrolling through my encounters which i (when creating) thought might give them pause. When they were level 6; (Using multiple(read:3) CR 9's in quick succession, 2 to 3 CR 7-8's together and then a fight which i calculated to be a CR 12 encounter. The tank didn't even go below half hp(in part due to bad rolls on my end and him rolling so well them instagibbing my bossmonster(~130 dmg with 2 people full attacking)

The one i'm trying to challenge has DR/- 3, High ac(26), High hp(over 100 when raging), Flurry for good attacks(+14 to hit), 12/10/14 saves and has immunity to most CMB checks due to a monk archetype.

I know DR would mess with him and most of the party(Bar the BBSF), i know that if they would ever fail a save(sos spells) problems would occur. They tend to roll high where as i'm a low roller.

They've essentially spoken to me about this and where happy with the roleplay aspect of the game, the lore and the overall world i've build so thats great! Combat wise, they wouldn't mind it being a bit more challenging (hopefully) without the instagib roll up new characters aspect.

So fellows giants, got any advice for me on how to challenge my group more and hopefully make combat a bit more enjoyable as i'm willing to cater to my players seeking more of a challenge there.

Thanks in advance and sorry for the wall of text but i figured offering more information would likely help.

[Aegis013]

The big key to challenging PCs with high numbers is using clever tactics.

The boss monster shouldn't necessarily be the one with the highest stats. It should be the most important one; the guy in the back dropping Solid Fog or Sleet Storm and then conjuring tons of extra mooks while the party is trying to get through the initial mooks.

Enemies who can keep away from the party by running, attacking and continuing to run. Or who use terrain to teleport behind cover and illusions to confuse the party.

Manipulate the terrain of the battlefield so there are surprises, traps in the middle of the fight. E.g. You charge the boss, but you hit the tripwire, and tanglefoot bags rain down from the ceiling. Everybody makes Reflex saves vs getting entangled.

Status conditions are powerful. Battlefield manipulation is powerful. Have the bad guys use them to their advantage.

[Gandariel]

Generic answer;

Have enemies that need to be defeated in different ways than being punched a lot.

If he makes many attacks DR should be very effective.

The final boss could have more "lives"
(Contingent heal, or something you invent, like a demonic pact resurrecting him as a demon)

Give a boost (a magic item) to the other three.

[Spore]

To be honest the DM that had the most balance in fights with is the one who summons new mooks into the fight until we're into our necks deep with enemies but then stops. He reacts to the performance in our fights. Not immediately but I've noticed him dropping a few extra monsters here or there. If outnumbered most outsiders with the summon SLA (that CAN fizzle) use that thing when they're dangerously outnumbered. A wounded fanatical acolyte would rather blow himself up with a whole bead of fireballs than give the heroes the win.

Have ressource intensive options at hand in order to counter a decent performance. People could the that motivated to kill the heroes by simply using a Candle of Invocation to create a Gate spell in hopes of gettin powers over an Archcreature of Chaos but first spawn several Protean Voidworms that unless defeated will leave the tear open and attract a CR 10 or CR 7 Protean.

See how many variables you can adjust simply by their performance? You can add 3-7 Voidworms, you can call two CR 7 Proteans in that scenario, you can call one (or even two) CR 10 Proteans just to aid. Playing with the number of encountered monsters is an art that I haven't mastered. But it is a very simple principle.