Vel'Koz is stronger in midlane or support
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Support isn't good. Vel'Koz support does lots of damage, which is good if your team isn't capable of carrying. It might save a game. But if you have a good adc, having a support that can amplify him is better, while you do even more damage from mid lane with additional resources.
Unless you have utility midlaner, its better to have a useful support. VelKoz does what he does, its what your team is missing out on.
Can you cs and position well so your not food for enemy mid and/or jungle? Mid. Velkoz primarily provides damage via poke and scales off items that enhance that. If your unable mechanically to do anything besides land abilities and cant CS don't bother with it mid.
Good luck Linda.
Support velkoz is better. I used to main velkoz mid but I got stuck in gold. I started maining velkoz support and I got to plat easily.