Reksai needs some Tuning. Her Early is too strong and she falls off too fast
Looking at her stats and my experience with her, she is really strong early game (under 20m) but then falls off really fast.
Most games run 25-30m long and by that point she is almost useless in the match.
Her issue is that she does too much Damage early (only by a hair tho) and then after 20 minutes she cant live long enough for being a Diver that cant get out.
My suggestion is to lower the damage on her E a bit early ranks and then when it is at Rank 5 add a Heal to it like % of the damage it does.
Also change her Passive to be a Heal value per Rage. So currently it is a flat value over 3s (say 150). If she has 100 Rage (max) she heals 33.3%/s of 150 (or 50 hps/s) and consumes 33.3%/s of Rage (or 33.3 rage/s)
BUT if she is at only 25 Rage it is consumed at 33.3% of 25 (8.33 rage/s) and heals 33.3% of 25% of 150 (12.5 hp/s) over 3s
I would change it to be she consumes 25 Rage/s and heals Flat amount/s max 4s This way the healing at lower values of Rage are more meaningful but is the same healing.