The tooltip states ''Shield of the Sun and Perseverance will now cool down 50% faster''.
This implies that the tactic increases the cooldown RATE (normally 1 s reduced from the ability cd every second) rather than the ability cooldown (here 30 seconds in both cases).
This would normally imply that the effective cooldown time for the abilities would be:
30 (s) / 1.5 (s/s) = 20 (s)
Instead what happens in game (which is much more intuitive) is the cooldown TIME is reduced by 50% (from 30 s to 15 s).
Proposed tooltip (if the 15s cd timer is not a bug):
''Shield Of The Sun and Perseverance will have their cooldown time reduced by 50%''
check similar wording for Chosen on image 2
