Disclaimer: this is purely an opinion and thoughts on what I think about these two sets and should be noted as such.

I think they kinda went partly in the wrong direction with them, almost, from both perspectives, people in PVP find it favorable, maybe not, same with PvE’ers.

• titanborn Strength 5 items: Adds 2-110 Weapon Damage and 28-1240 Physical Penetration. While in combat, this bonus doubles to 5-220 Weapon Damage and 57-2480 Physical Penetration when you are under 75% Health. While in combat, this bonus quadruples to 10-440 Weapon Damage and 115-4960 Physical Penetration when you are under 50% Health.
• True-sworn fury 5 items: Adds 16-708 Spell Critical and increases your Critical Damage by 0-4%. While in combat, this bonus doubles to 32-1416 Spell Critical and 0-8% increased Critical Damage when you are under 75% Health. While in combat this bonus quadruples to 65-2832 Spell Critical and 0-16% increased Critical Damage when you are under 50% Health.

But wouldn’t it be somewhat better if their mechanics and bonuses were reversed?

• new titanborn Strength 5 items: While in combat for more than 1 second, Adds 10-440 Weapon Damage and 115-4960 Physical Penetration. this bonus is reduced to 5-220 Weapon Damage and 57-2480 Physical Penetration when you are below 100% Health. this bonus is further reduced to 2-110 Weapon Damage and 28-1240 Physical Penetration when you are below 75% Health.
• new True-sworn fury 5 items: While in combat for more than 1 second, Adds 65-2832 Spell Critical and increases your Critical Damage by 0-16%. this bonus is reduced to 32-1416 Spell Critical and 0-8% increased Critical Damage when you are below 100% Health. this bonus is further reduced to 16-708 Spell Critical and 0-4% increased Critical Damage when you are below 75% Health.

From this perspective, in PvE, these effects would reward players who value staying alive, as well as giving healers in PvE (group dungeons, trials, etc.) more importance in their role as by staying at 100% health, you would be rewarding the wearer by allowing them to keep the damage buffs from those sets maximized at nearly all times and at the same time satisfying dedicated healers. And possibly those who would sacrifice some ability slots for heals or even use things like the ring of the pale order. plus a dead DPS equals no DPS.

In PvP however, that is a completely different ballpark, there are those who would seek to use these particular bonuses for ganking, ball groups, etc. ball groups with healers that is fine as it should be rewarding to a well co-ordinated group of players, but there are some elements to it that could cause a few problems, but, in a way that is where the one second delay comes in, to make sure that opposing players who do not see it coming (because sneak attacks alone are powerful on their own under the right circumstances based on how a player builds their character.) end up suffering the worst of it as gankers can be a problem to the unprepared and possibly decide to either deal with it or rant about it. But if somebody decides to fight you head on without sneaking, who knows. Either way, by dealing sufficient damage and doing your best to keep them below those thresholds, you reward yourself against those set users by weakening them in the sets regard, pushing them to use potions or spend resources on some occasions to keep themselves topped up on health thus keeping the bonus to maximize damage, the time spent doing that equals time spent not damaging your target and giving them a partial opening of attack, but in PvP, either side of the battlefield can change at will unexpectedly.