The Viktor build for Top is Shadowflame, Stormsurge, and Luden's Companion. This LoL Viktor guide for Top at Platinum+ on 14.3 includes runes, items, skill order, and counters.
Viktor Counters
50.7%
(-0.4%)
50.5%
(+2.1%)
0.1%
(-0.0%)
1.5%
(+0.1%)
880
(+4)