Hey, remember that Oliver has a son? Well, he'll be out of Star City, in another city that could have been a possibility for the mom's relocation, so why not make that true and have Oliver coincidentally see the mom, and a young man who just happens to bear some resemblance to himself, in the coffee shop that the Flash Team frequents?
"I have to put the fates of Kendra and Carter on hold while I go stake out the home of the woman who possibly lied to me about bearing my child. HEY, I got the boy's hair sample in the process! Barry can you run a quick paternity test? Thanks!"
"Sure thing buddy. Oh HEY Felicity! Pay no attention to this piece of paper I'm holding. I promised Oliver I wouldn't show it to anyone, even you. Take it up with hi-- Stop asking me fo--- OKAY! Sheesh, you're scary when you're angry so I'll just hand it over."
*Cut back to random safe house*
"Whiskey Tango Foxtrot, Oliver? You just lied to me about something that monumentally changes your life. Yes, I suppose I could have waited to broach this very serious subject until after we dealt with the new winged folks and the madman threatening to destroy both our cities, but instead I think we will just be done because you obviously will never trust me."
"Felicity wait--- *sigh* Okay everyone, here's how we take down Savage. And by "we" I mean only myself, Barry, and the wingnuts. SUIT UP! ...except for Thea, Laurel, and Diggle. You guys are going to wait here and conveniently follow my request for you to "stay out of it" despite all of you telling me to "shove it" in the past when I have asked that."
*Cut to warehouse battle*
"The gauntlets aren't working, Barry, you'll die! And now that I'm touching the staff, I will also die. You should run away since you are at least fast enough to outrun the blast. GO!"
"Aha! So THIS is why I time travel! Convenient reset button, here I come!"
*Cut back to house*
"Oliver, I time travel if I run too fast. And I just did, when we try to take on Savage. Our plan doesn't work because Kendra can't access her powers. Whatever Carter's doing, it doesn't work. Also, don't tell Felicity about the positive paternity test on the son that you haven't even asked me to perform yet. It doesn't end well."
"Good to know. We'll have Cisco talk to Kendra because he loves her and THAT will let her fully emerge. Hopefully she'll remember something useful on how to defeat Savage, Cisco will build better gauntlets, and I promise I'll have my head in the game this time around and use everyone because I definitely know by now that there is strength in numbers. POOF! Scratch one Vandal Savage. OH, and I think I'll keep my visits to my son (who I can't tell that I am his dad) a secret from everyone I know and love, because that most definitely will not cause suspicion later this season."
*Cut to Merlyn in the warehouse standing over Savage's ashes (conveniently just left there on the floor), metaphorically twirling his nonexistent mustache*
"You owe me one, buddy!"
