I'm thinking about league-starting hit-based glad with a small dip into bleed to get the guaranteed 20% explode. As others have pointed out, gladiator has several strong nodes but lacks a feeling of cohesion. This is an attempt to leverage the strong points of glad (block, bleed explosions, not the DPS) to farm early content like expedition, harbinger, or breach that greatly benefit from applying explosions over a large area.

(This is not intended to be uber-viable but should be able to easily get watchstones by swapping to something with high single-target like dual strike and temporarily speccing War of Attrition).

POB link - level 100 still trying to decide what to cut

Core ideas:

• Bleed damage looks mid, unless using specific skills (lacerate of hemorrhage) or very slow slams.
• Lacerate of hemorrhage coverage is tiny, thus negating the clear-speed benefits of bleed explosions.
• Gladiator has lost its DoT-based damage scaling (weapon master axe also affects hits, aggravated can be found elsewhere).
• Combining buffed bleed gladiator explosions with a skill with better AoE, high hit rate (>6 APS) and reasonable bleed chance (40% in this PoB) will give clear similar to old bleed bow or CF-champ with higher DPS on bosses and rares. (CF champ is conceptually similar in that it used gladiator bleed explode but didn't care about bleed DPS.)
• Mana costs and defensive auras are much worse in 3.24 so going Blood Magic + eternal blessing Pride frees up a ton of space in this type of build that previously went to solving mana.
• Dual wield > shield: Determined survivor seems to be begging to be played as dual-wield. Going from 50% block to 40% block / 20% MORE attack speed + getting all the DW attack speed on the passive tree is a no-brainer, especially given how much attack speed melee builds have lost in 3.25, and how buffed block chance is near the duelist starting area.
• Defenses: Gladiator can combine ~90% avoidance (lucky + versatile combatant) with 5 endurance charges and max res (85%+ if you really want to invest in it) for a very tanky playstyle without needing to rely on high armor (~20k in this PoB).

Items:

• The only items required for this build are a 10+ passive Axe / Sword cluster jewel with "small nodes have 35% increased effect" and 2x Varunastras. Varunastra is an extremely cheap unique and this build is intended to function in trade league in week 1 with basically 0 gear.
• Eventually you would probably be better off switching to a combo of a rare axe, claw and/or mace but you won't be able to use reave anymore. I will probably just switch to whatever is meta at that point.
• I put a brass dome in the pob to see what my armor would look like but this is obviously completely unnecessary to progress, any 6L should be fine since most of our defense is endurance charge & block.

Skills:

• The main selling point of reave is that it has a ton of AOE built into it and a decent vaal version for difficult moments. Seriously go look at a full stacked 20% quality reave with some %aoe scaling vs. lacerate and tell me which one looks more fun to play.
• The rest of the skills are pretty self-explanatory, it uses 2x 3Links and 2 x 4Links in case you end up running Kaoms roots. Melee builds have lots of free sockets now due to the removal of totems. You can fill these slots with w/e if you want.
• Retaliation skills might be good. If that's the case, I could definitely see using a 4L retaliation setup and investing into Measured Retaliation.
• You can swap to dual strike of ambidextry for watchstone bosses to get an easy 4M DPS.

What to farm:

• This should do very well against any league content that generates dense packs (expedition, harbinger, or breach as mentioned). You will be basically invulnerable to small hits with life on block, 90% block and endurance charges.