Elite Hunter's Mark

You choose a creature you can see within range and mystically mark it as your quarry. Until the spell ends, you deal an extra 1d6 damage to the target whenever you hit it with a weapon attack, and you have advantage on any Wisdom (Perception) or Wisdom (Survival) check you make to find it. If the target drops to 0 hit points before this spell ends, you can use a bonus action on a subsequent turn of yours to mark a new creature.

Due to training, considerable experience and the constant use of hunters mark, concentration is greatly improved. Chances of maintaining concentration even while sustaining damage are improved to the point that the concentration checks add + 4 to the roll and are rolled with advantage . Concentration is automatically lost when you sustain damage in excess of 75% of your hit-points.

If the characters combined Intelligence and Wisdom modifier exceeds (+5) then Elite Hunters Mark can be maintained even when casting one additional concentration required spell.  

At Higher Levels. When you cast this spell using a spell slot of 3rd or 4th level, you can maintain your concentration on the spell for up to 8 hours. When you use a spell slot of 5th level or higher, you can maintain your concentration on the spell for up to 24 hours.

Elite Hunters Mark will stack with Slayers Prey and other melee/ranged weapon modified or spell attacks