Leona's damaging spells affect the target with Sunlight for 1.5 seconds. When allied champions deal damage to those targets they consume the Sunlight debuff to deal 32−168 (at levels 1-18) additional magic damage. The amount is increased every 2 levels. Leona is unable to activate the additional damage herself.
i think they should adjust the passive to,
Leona can activate additional magic damage herself (or perhaps 50% effect) if there are no ally champion in 1000 range.
Leona will never be a fighter if she cant activate herself,
and does the damage penetrate the enemy MR with leona's MPen or with the procc'ing champion's?
(in OFA i mean)