User blog comment:Hitsuji Mamoru/FGO-style Servant Creation Room/@comment-34705125-20180419131325/@comment-34705125-20180423094153

@Hitsuji Mamoru, the 4 turns effect is directly linked to the damage he did against the Philistines (and to the lion as well, though this part is relatively insignificant) :

1) When he was on his way to ask for a Philistine woman's hand in marriage he was attacked by a lion. According to Biblical Lore, he was empowered by God and he ripped apart the Lion with his bare hands.

2) Secondly, Samson killed 30 Philistines for their garments (items of clothing).

3) Thirdly, He gathered up 300 foxes, He then attached a burning torch to each pair of foxes' tails and turned them loose in the grain fields and olive groves of the Philistines causing damage to their crop fields.

4) Lastly, In revenge, Samson slaughtered many more Philistines, saying, "I have done to them what they did to me. Samson then took refuge in a cave in the rock of Etam. An army of Philistines came to the Tribe of Judah and demanded that 3,000 men of Judah deliver them Samson.With Samson's consent, they tied him with two new ropes and were about to hand him over to the Philistines when he broke free of the ropes. Using the jawbone of a donkey, he slew 1,000 Philistines. (This part is the lore / information for Samson's Noble Phantasm by the way).