Allen's magic is capable of killing Ottar if he is not serious. Ottar's magic is equal to Bell's Argo-Vesta, which in turn, when fully charged, increases Bell's attack power by 3 levels (presumably).

5+3 = a maximum level 8 attack.

Ottarl is a level 7 though. Does his magic simply strengthen that attack of his or does it act similar to hell kaios?

Is allen's also an enchantment or an attack magic cause it is a self buff type spell

Ottar's magic is an enchantment, but it strengthens only one attack. Also, when Ottar prepared to defend himself against Allen's magic he only changed his position so he could use his full strength, he never recited Hildis Vini's chant. So using Hildis Vini as a comparison is completely wrong.

Considering Ottar's Strength stat it is minimum a high Level 7 attack. Maybe higher.

Allens Magic greatly increases his speed, the magic itself might also increase his Atk power, but then he also probably has a passive skill where his speed increases his atk power, so the spell scales very well with his kit. Combine that with the potential DA spearman, his damage output is insanely strong so much that Ottar respects it.

• Those of course are added assumptions about his other abilities, but regardless Ottar respects it and he is a maxed End level 7 with the Strong Body DA at level G. That says something about its power.

Does allen also keeps getting faster as he keeps moving if there is no limit to how fast he can become?

He can indeed potentially keep growing faster, but he isn't constantly doing so. Otherwise Bell would have never been able to outpace him.

And ottarl's magic just remains in his sword increasing its attack power and not flows like hell kaios or getsuga tensho from bleach?

The magic is an enchantment not a charged attack, so it boosts an attack's power by a set amount instead of constantly increasing.

If with "flow" you mean continue moving towarss the enemy by itself, I guess so, considering it struck Udaeus although Ottar was far away form it.

Was ottarl's magic described in any more detail anywhere? like i know when aisha uses hell kaios, it always travels on a surface. not just in air like getsuga tensho from bleach or zoro form OP cutting through air.

Does he have the same restrictions? allen's magic sounds too OP. it should have some negative effects too right?