null magic mantle start?

Probably better to just start boots and dodge skillshots. Much more sustain from the pots, boots become easily upgradable

Or flask/pots if you're really worried about it. For someone like annie Shield/pot is more than enough.

I start Null-Mantle against insanely high-damage early assassin-level burst-power opponents like Viktor. I also often combine it with 09/21/00 Masteries just because their early-game damage is often ridiculously over-tuned.

If you're a mana champ that needs an easier early game, flask pots is probably the best option. If you're not mana and you face a skillshot dependant poke champ, boots is probably the best. If you're like a non-mana champ against a non-skillshot poke champ, you can consider this against ruby crystal + 2 pots (hp helps vs both magic and physical dmg) or cloth armor +5pots (non-skillshot dependant usually means they're using auto attacks to harass. Cloth will help in this case).

The only champ where cloth and boots don't help is probably against Vladimir. I haven't tested null cloak + pot out yet, but I feel like 1 pot is so little protection against poke, even with the MRes. I would probably go for ruby 2 pots or just an offensive item and try to all-in. If I'm a mana champ, I would definitely go flask + 3 pots, though.